OpenSSL

Vulnerabilities

If you think you have found a security bug in OpenSSL, please report it to us.

Show issues fixed only in OpenSSL 3.3, 3.2, 3.1, 3.0, 1.1.1, 1.1.0, 1.0.2, 1.0.1, 1.0.0, 0.9.8, 0.9.7, 0.9.6, or all versions

Fixed in OpenSSL 1.0.2

OpenSSL 1.0.2 is out of support since 1st January 2020 and is no longer receiving updates. Extended support is available from OpenSSL Software Services for premium support customers.

Jump to year: 2024, 2023, 2022, 2021, 2020, 2019, 2018, 2017, 2016, 2015

2024

CVE-2024-0727 PKCS12 Decoding crashes [Low severity] 25 January 2024:

Issue summary: Processing a maliciously formatted PKCS12 file may lead OpenSSL to crash leading to a potential Denial of Service attack

Impact summary: Applications loading files in the PKCS12 format from untrusted sources might terminate abruptly.

A file in PKCS12 format can contain certificates and keys and may come from an untrusted source. The PKCS12 specification allows certain fields to be NULL, but OpenSSL does not correctly check for this case. This can lead to a NULL pointer dereference that results in OpenSSL crashing. If an application processes PKCS12 files from an untrusted source using the OpenSSL APIs then that application will be vulnerable to this issue.

OpenSSL APIs that are vulnerable to this are: PKCS12_parse(), PKCS12_unpack_p7data(), PKCS12_unpack_p7encdata(), PKCS12_unpack_authsafes() and PKCS12_newpass().

We have also fixed a similar issue in SMIME_write_PKCS7(). However since this function is related to writing data we do not consider it security significant.

The FIPS modules in 3.2, 3.1 and 3.0 are not affected by this issue.

Found by Bahaa Naamneh (Crosspoint Labs). Fix developed by Matt Caswell.

• Fixed in OpenSSL 1.0.2zj (premium support) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 3.2.1, OpenSSL 3.1.5, OpenSSL 3.0.13, OpenSSL 1.1.1x

2023

CVE-2023-5678 Excessive time spent in DH check / generation with large Q parameter value [LOW severity] 06 November 2023:

Issue summary: Generating excessively long X9.42 DH keys or checking excessively long X9.42 DH keys or parameters may be very slow.

Impact summary: Applications that use the functions DH_generate_key() to generate an X9.42 DH key may experience long delays. Likewise, applications that use DH_check_pub_key(), DH_check_pub_key_ex() or EVP_PKEY_public_check() to check an X9.42 DH key or X9.42 DH parameters may experience long delays. Where the key or parameters that are being checked have been obtained from an untrusted source this may lead to a Denial of Service.

While DH_check() performs all the necessary checks (as of CVE-2023-3817), DH_check_pub_key() doesn't make any of these checks, and is therefore vulnerable for excessively large P and Q parameters.

Likewise, while DH_generate_key() performs a check for an excessively large P, it doesn't check for an excessively large Q.

An application that calls DH_generate_key() or DH_check_pub_key() and supplies a key or parameters obtained from an untrusted source could be vulnerable to a Denial of Service attack.

DH_generate_key() and DH_check_pub_key() are also called by a number of other OpenSSL functions. An application calling any of those other functions may similarly be affected. The other functions affected by this are DH_check_pub_key_ex(), EVP_PKEY_public_check(), and EVP_PKEY_generate().

Also vulnerable are the OpenSSL pkey command line application when using the "-pubcheck" option, as well as the OpenSSL genpkey command line application.

The OpenSSL SSL/TLS implementation is not affected by this issue.

The OpenSSL 3.0 and 3.1 FIPS providers are not affected by this issue.

Found by David Benjamin (Google). Fix developed by Richard Levitte.

• Fixed in OpenSSL 1.0.2zj (premium support) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.1.1x, OpenSSL 3.0.13, OpenSSL 3.1.5

CVE-2023-3817 Excessive time spent checking DH q parameter value [Low severity] 31 July 2023:

Issue summary: Checking excessively long DH keys or parameters may be very slow.

Impact summary: Applications that use the functions DH_check(), DH_check_ex() or EVP_PKEY_param_check() to check a DH key or DH parameters may experience long delays. Where the key or parameters that are being checked have been obtained from an untrusted source this may lead to a Denial of Service.

The function DH_check() performs various checks on DH parameters. After fixing CVE-2023-3446 it was discovered that a large q parameter value can also trigger an overly long computation during some of these checks. A correct q value, if present, cannot be larger than the modulus p parameter, thus it is unnecessary to perform these checks if q is larger than p.

An application that calls DH_check() and supplies a key or parameters obtained from an untrusted source could be vulnerable to a Denial of Service attack.

The function DH_check() is itself called by a number of other OpenSSL functions. An application calling any of those other functions may similarly be affected. The other functions affected by this are DH_check_ex() and EVP_PKEY_param_check().

Also vulnerable are the OpenSSL dhparam and pkeyparam command line applications when using the "-check" option.

The OpenSSL SSL/TLS implementation is not affected by this issue.

The OpenSSL 3.0 and 3.1 FIPS providers are not affected by this issue.

Found by Bernd Edlinger. Fix developed by Tomas Mraz.

• Fixed in OpenSSL 1.0.2zi (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 3.1.2, OpenSSL 3.0.10, OpenSSL 1.1.1v

CVE-2023-3446 Excessive time spent checking DH keys and parameters [Low severity] 13 July 2023:

Issue summary: Checking excessively long DH keys or parameters may be very slow.

Impact summary: Applications that use the functions DH_check(), DH_check_ex() or EVP_PKEY_param_check() to check a DH key or DH parameters may experience long delays. Where the key or parameters that are being checked have been obtained from an untrusted source this may lead to a Denial of Service.

The function DH_check() performs various checks on DH parameters. One of those checks confirms that the modulus ('p' parameter) is not too large. Trying to use a very large modulus is slow and OpenSSL will not normally use a modulus which is over 10,000 bits in length.

However the DH_check() function checks numerous aspects of the key or parameters that have been supplied. Some of those checks use the supplied modulus value even if it has already been found to be too large.

An application that calls DH_check() and supplies a key or parameters obtained from an untrusted source could be vulernable to a Denial of Service attack.

The function DH_check() is itself called by a number of other OpenSSL functions. An application calling any of those other functions may similarly be affected. The other functions affected by this are DH_check_ex() and EVP_PKEY_param_check().

Also vulnerable are the OpenSSL dhparam and pkeyparam command line applications when using the '-check' option.

The OpenSSL SSL/TLS implementation is not affected by this issue. The OpenSSL 3.0 and 3.1 FIPS providers are not affected by this issue.

Found by OSSfuzz. Fix developed by Matt Caswell.

• Fixed in OpenSSL 1.0.2zi (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 3.1.2, OpenSSL 3.0.10, OpenSSL 1.1.1v

CVE-2023-2650 Possible DoS translating ASN.1 object identifiers [Moderate severity] 30 May 2023:

Issue summary: Processing some specially crafted ASN.1 object identifiers or data containing them may be very slow.

Impact summary: Applications that use OBJ_obj2txt() directly, or use any of the OpenSSL subsystems OCSP, PKCS7/SMIME, CMS, CMP/CRMF or TS with no message size limit may experience notable to very long delays when processing those messages, which may lead to a Denial of Service.

An OBJECT IDENTIFIER is composed of a series of numbers - sub-identifiers - most of which have no size limit. OBJ_obj2txt() may be used to translate an ASN.1 OBJECT IDENTIFIER given in DER encoding form (using the OpenSSL type ASN1_OBJECT) to its canonical numeric text form, which are the sub-identifiers of the OBJECT IDENTIFIER in decimal form, separated by periods.

When one of the sub-identifiers in the OBJECT IDENTIFIER is very large (these are sizes that are seen as absurdly large, taking up tens or hundreds of KiBs), the translation to a decimal number in text may take a very long time. The time complexity is O(n^2) with 'n' being the size of the sub-identifiers in bytes (*).

With OpenSSL 3.0, support to fetch cryptographic algorithms using names / identifiers in string form was introduced. This includes using OBJECT IDENTIFIERs in canonical numeric text form as identifiers for fetching algorithms.

Such OBJECT IDENTIFIERs may be received through the ASN.1 structure AlgorithmIdentifier, which is commonly used in multiple protocols to specify what cryptographic algorithm should be used to sign or verify, encrypt or decrypt, or digest passed data.

Applications that call OBJ_obj2txt() directly with untrusted data are affected, with any version of OpenSSL. If the use is for the mere purpose of display, the severity is considered low.

In OpenSSL 3.0 and newer, this affects the subsystems OCSP, PKCS7/SMIME, CMS, CMP/CRMF or TS. It also impacts anything that processes X.509 certificates, including simple things like verifying its signature.

The impact on TLS is relatively low, because all versions of OpenSSL have a 100KiB limit on the peer's certificate chain. Additionally, this only impacts clients, or servers that have explicitly enabled client authentication.

In OpenSSL 1.1.1 and 1.0.2, this only affects displaying diverse objects, such as X.509 certificates. This is assumed to not happen in such a way that it would cause a Denial of Service, so these versions are considered not affected by this issue in such a way that it would be cause for concern, and the severity is therefore considered low.

Found by OSSFuzz. Found by Matt Caswell. Fix developed by Richard Levitte.

• Fixed in OpenSSL 1.0.2zh (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 3.1.1, OpenSSL 3.0.9, OpenSSL 1.1.1u

CVE-2023-0465 Invalid certificate policies in leaf certificates are silently ignored [Low severity] 23 March 2023:

Applications that use a non-default option when verifying certificates may be vulnerable to an attack from a malicious CA to circumvent certain checks.

Invalid certificate policies in leaf certificates are silently ignored by OpenSSL and other certificate policy checks are skipped for that certificate. A malicious CA could use this to deliberately assert invalid certificate policies in order to circumvent policy checking on the certificate altogether.

Policy processing is disabled by default but can be enabled by passing the `-policy` argument to the command line utilities or by calling the `X509_VERIFY_PARAM_set1_policies()` function.

Found by David Benjamin (Google). Fix developed by Matt Caswell.

• Fixed in OpenSSL 1.0.2zh (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 3.1.1, OpenSSL 3.0.9, OpenSSL 1.1.1u

CVE-2023-0466 Certificate policy check not enabled [Low severity] 21 March 2023:

The function X509_VERIFY_PARAM_add0_policy() is documented to implicitly enable the certificate policy check when doing certificate verification. However the implementation of the function does not enable the check which allows certificates with invalid or incorrect policies to pass the certificate verification.

As suddenly enabling the policy check could break existing deployments it was decided to keep the existing behavior of the X509_VERIFY_PARAM_add0_policy() function.

Instead the applications that require OpenSSL to perform certificate policy check need to use X509_VERIFY_PARAM_set1_policies() or explicitly enable the policy check by calling X509_VERIFY_PARAM_set_flags() with the X509_V_FLAG_POLICY_CHECK flag argument.

Certificate policy checks are disabled by default in OpenSSL and are not commonly used by applications.

Found by David Benjamin (Google). Fix developed by Tomas Mraz.

• Fixed in OpenSSL 1.0.2zh (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 3.1.1, OpenSSL 3.0.9, OpenSSL 1.1.1u

CVE-2023-0464 Excessive Resource Usage Verifying X.509 Policy Constraints [Low severity] 21 March 2023:

A security vulnerability has been identified in all supported versions

of OpenSSL related to the verification of X.509 certificate chains that include policy constraints. Attackers may be able to exploit this vulnerability by creating a malicious certificate chain that triggers exponential use of computational resources, leading to a denial-of-service (DoS) attack on affected systems.

Policy processing is disabled by default but can be enabled by passing the `-policy` argument to the command line utilities or by calling the `X509_VERIFY_PARAM_set1_policies()` function.

Found by David Benjamin (Google). Fix developed by Dr Paul Dale.

• Fixed in OpenSSL 1.0.2zh (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 3.1.1, OpenSSL 3.0.9, OpenSSL 1.1.1u

CVE-2023-0286 X.400 address type confusion in X.509 GeneralName [High severity] 07 February 2023:

There is a type confusion vulnerability relating to X.400 address processing inside an X.509 GeneralName. X.400 addresses were parsed as an ASN1_STRING but the public structure definition for GENERAL_NAME incorrectly specified the type of the x400Address field as ASN1_TYPE. This field is subsequently interpreted by the OpenSSL function GENERAL_NAME_cmp as an ASN1_TYPE rather than an ASN1_STRING.

When CRL checking is enabled (i.e. the application sets the X509_V_FLAG_CRL_CHECK flag), this vulnerability may allow an attacker to pass arbitrary pointers to a memcmp call, enabling them to read memory contents or enact a denial of service. In most cases, the attack requires the attacker to provide both the certificate chain and CRL, neither of which need to have a valid signature. If the attacker only controls one of these inputs, the other input must already contain an X.400 address as a CRL distribution point, which is uncommon. As such, this vulnerability is most likely to only affect applications which have implemented their own functionality for retrieving CRLs over a network.

Found by David Benjamin (Google). Fix developed by Hugo Landau.

• Fixed in OpenSSL 1.0.2zg (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 3.0.8, OpenSSL 1.1.1t

CVE-2023-0215 Use-after-free following BIO_new_NDEF [Moderate severity] 07 February 2023:

The public API function BIO_new_NDEF is a helper function used for streaming ASN.1 data via a BIO. It is primarily used internally to OpenSSL to support the SMIME, CMS and PKCS7 streaming capabilities, but may also be called directly by end user applications.

The function receives a BIO from the caller, prepends a new BIO_f_asn1 filter BIO onto the front of it to form a BIO chain, and then returns the new head of the BIO chain to the caller. Under certain conditions, for example if a CMS recipient public key is invalid, the new filter BIO is freed and the function returns a NULL result indicating a failure. However, in this case, the BIO chain is not properly cleaned up and the BIO passed by the caller still retains internal pointers to the previously freed filter BIO. If the caller then goes on to call BIO_pop() on the BIO then a use-after-free will occur. This will most likely result in a crash.

This scenario occurs directly in the internal function B64_write_ASN1() which may cause BIO_new_NDEF() to be called and will subsequently call BIO_pop() on the BIO. This internal function is in turn called by the public API functions PEM_write_bio_ASN1_stream, PEM_write_bio_CMS_stream, PEM_write_bio_PKCS7_stream, SMIME_write_ASN1, SMIME_write_CMS and SMIME_write_PKCS7.

Other public API functions that may be impacted by this include i2d_ASN1_bio_stream, BIO_new_CMS, BIO_new_PKCS7, i2d_CMS_bio_stream and i2d_PKCS7_bio_stream.

The OpenSSL cms and smime command line applications are similarly affected.

Found by Octavio Galland (Max Planck Institute for Security and Privacy). Found by Marcel Böhme (Max Planck Institute for Security and Privacy). Fix developed by Viktor Dukhovni. Fix developed by Matt Caswell.

• Fixed in OpenSSL 1.0.2zg (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 3.0.8, OpenSSL 1.1.1t

CVE-2022-4304 Timing Oracle in RSA Decryption [Moderate severity] 07 February 2023:

A timing based side channel exists in the OpenSSL RSA Decryption implementation which could be sufficient to recover a plaintext across a network in a Bleichenbacher style attack. To achieve a successful decryption an attacker would have to be able to send a very large number of trial messages for decryption. The vulnerability affects all RSA padding modes: PKCS#1 v1.5, RSA-OEAP and RSASVE.

For example, in a TLS connection, RSA is commonly used by a client to send an encrypted pre-master secret to the server. An attacker that had observed a genuine connection between a client and a server could use this flaw to send trial messages to the server and record the time taken to process them. After a sufficiently large number of messages the attacker could recover the pre-master secret used for the original connection and thus be able to decrypt the application data sent over that connection.

Found by Hubert Kario from Red Hat. Fix developed by Dmitry Belyavsky from Red Hat. Fix developed by Hubert Kario from Red Hat.

• Fixed in OpenSSL 1.0.2zg (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 3.0.8, OpenSSL 1.1.1t

2022

CVE-2022-2068 The c_rehash script allows command injection [Moderate severity] 21 June 2022:

In addition to the c_rehash shell command injection identified in CVE-2022-1292, further circumstances where the c_rehash script does not properly sanitise shell metacharacters to prevent command injection were found by code review. When the CVE-2022-1292 was fixed it was not discovered that there are other places in the script where the file names of certificates being hashed were possibly passed to a command executed through the shell. This script is distributed by some operating systems in a manner where it is automatically executed. On such operating systems, an attacker could execute arbitrary commands with the privileges of the script. Use of the c_rehash script is considered obsolete and should be replaced by the OpenSSL rehash command line tool.

Found by Chancen (Qingteng 73lab).

• Fixed in OpenSSL 1.0.2zf (premium support) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 3.0.4, OpenSSL 1.1.1p

CVE-2022-1292 The c_rehash script allows command injection [Moderate severity] 03 May 2022:

The c_rehash script does not properly sanitise shell metacharacters to prevent command injection. This script is distributed by some operating systems in a manner where it is automatically executed. On such operating systems, an attacker could execute arbitrary commands with the privileges of the script. Use of the c_rehash script is considered obsolete and should be replaced by the OpenSSL rehash command line tool.

Found by Elison Niven (Sophos).

• Fixed in OpenSSL 1.0.2ze (premium support) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 3.0.3, OpenSSL 1.1.1o

CVE-2022-0778 Infinite loop in BN_mod_sqrt() reachable when parsing certificates [High severity] 15 March 2022:

The BN_mod_sqrt() function, which computes a modular square root, contains a bug that can cause it to loop forever for non-prime moduli. Internally this function is used when parsing certificates that contain elliptic curve public keys in compressed form or explicit elliptic curve parameters with a base point encoded in compressed form. It is possible to trigger the infinite loop by crafting a certificate that has invalid explicit curve parameters. Since certificate parsing happens prior to verification of the certificate signature, any process that parses an externally supplied certificate may thus be subject to a denial of service attack. The infinite loop can also be reached when parsing crafted private keys as they can contain explicit elliptic curve parameters. Thus vulnerable situations include: - TLS clients consuming server certificates - TLS servers consuming client certificates - Hosting providers taking certificates or private keys from customers - Certificate authorities parsing certification requests from subscribers - Anything else which parses ASN.1 elliptic curve parameters Also any other applications that use the BN_mod_sqrt() where the attacker can control the parameter values are vulnerable to this DoS issue. In the OpenSSL 1.0.2 version the public key is not parsed during initial parsing of the certificate which makes it slightly harder to trigger the infinite loop. However any operation which requires the public key from the certificate will trigger the infinite loop. In particular the attacker can use a self-signed certificate to trigger the loop during verification of the certificate signature. This issue affects OpenSSL versions 1.0.2, 1.1.1 and 3.0. It was addressed in the releases of 1.1.1n and 3.0.2 on the 15th March 2022.

Found by Tavis Ormandy (Google).

• Fixed in OpenSSL 1.0.2zd (premium support) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 3.0.2, OpenSSL 1.1.1n

CVE-2021-4160 BN_mod_exp may produce incorrect results on MIPS [Moderate severity] 28 January 2022:

There is a carry propagation bug in the MIPS32 and MIPS64 squaring procedure. Many EC algorithms are affected, including some of the TLS 1.3 default curves. Impact was not analyzed in detail, because the pre-requisites for attack are considered unlikely and include reusing private keys. Analysis suggests that attacks against RSA and DSA as a result of this defect would be very difficult to perform and are not believed likely. Attacks against DH are considered just feasible (although very difficult) because most of the work necessary to deduce information about a private key may be performed offline. The amount of resources required for such an attack would be significant. However, for an attack on TLS to be meaningful, the server would have to share the DH private key among multiple clients, which is no longer an option since CVE-2016-0701. This issue affects OpenSSL versions 1.0.2, 1.1.1 and 3.0.0. It was addressed in the releases of 1.1.1m and 3.0.1 on the 15th of December 2021, and the release of 1.0.2zc on the 22nd of February 2022. The issue only affects OpenSSL on MIPS platforms.

Found by Bernd Edlinger.

• Fixed in OpenSSL 1.0.2zc (premium support) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 3.0.1, OpenSSL 1.1.1m

2021

CVE-2021-3712 Read buffer overruns processing ASN.1 strings [Moderate severity] 24 August 2021:

ASN.1 strings are represented internally within OpenSSL as an ASN1_STRING structure which contains a buffer holding the string data and a field holding the buffer length. This contrasts with normal C strings which are repesented as a buffer for the string data which is terminated with a NUL (0) byte. Although not a strict requirement, ASN.1 strings that are parsed using OpenSSL's own "d2i" functions (and other similar parsing functions) as well as any string whose value has been set with the ASN1_STRING_set() function will additionally NUL terminate the byte array in the ASN1_STRING structure. However, it is possible for applications to directly construct valid ASN1_STRING structures which do not NUL terminate the byte array by directly setting the "data" and "length" fields in the ASN1_STRING array. This can also happen by using the ASN1_STRING_set0() function. Numerous OpenSSL functions that print ASN.1 data have been found to assume that the ASN1_STRING byte array will be NUL terminated, even though this is not guaranteed for strings that have been directly constructed. Where an application requests an ASN.1 structure to be printed, and where that ASN.1 structure contains ASN1_STRINGs that have been directly constructed by the application without NUL terminating the "data" field, then a read buffer overrun can occur. The same thing can also occur during name constraints processing of certificates (for example if a certificate has been directly constructed by the application instead of loading it via the OpenSSL parsing functions, and the certificate contains non NUL terminated ASN1_STRING structures). It can also occur in the X509_get1_email(), X509_REQ_get1_email() and X509_get1_ocsp() functions. If a malicious actor can cause an application to directly construct an ASN1_STRING and then process it through one of the affected OpenSSL functions then this issue could be hit. This might result in a crash (causing a Denial of Service attack). It could also result in the disclosure of private memory contents (such as private keys, or sensitive plaintext).

Found by Ingo Schwarze.

• Fixed in OpenSSL 1.0.2za (premium support) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.1.1l

CVE-2021-23841 Null pointer deref in X509_issuer_and_serial_hash() [Moderate severity] 16 February 2021:

The OpenSSL public API function X509_issuer_and_serial_hash() attempts to create a unique hash value based on the issuer and serial number data contained within an X509 certificate. However it fails to correctly handle any errors that may occur while parsing the issuer field (which might occur if the issuer field is maliciously constructed). This may subsequently result in a NULL pointer deref and a crash leading to a potential denial of service attack. The function X509_issuer_and_serial_hash() is never directly called by OpenSSL itself so applications are only vulnerable if they use this function directly and they use it on certificates that may have been obtained from untrusted sources. OpenSSL versions 1.1.1i and below are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1j. OpenSSL versions 1.0.2x and below are affected by this issue. However OpenSSL 1.0.2 is out of support and no longer receiving public updates. Premium support customers of OpenSSL 1.0.2 should upgrade to 1.0.2y. Other users should upgrade to 1.1.1j.

Found by Tavis Ormandy (Google).

• Fixed in OpenSSL 1.0.2y (premium support) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.1.1j

CVE-2021-23840 Integer overflow in CipherUpdate [Low severity] 16 February 2021:

Calls to EVP_CipherUpdate, EVP_EncryptUpdate and EVP_DecryptUpdate may overflow the output length argument in some cases where the input length is close to the maximum permissable length for an integer on the platform. In such cases the return value from the function call will be 1 (indicating success), but the output length value will be negative. This could cause applications to behave incorrectly or crash. OpenSSL versions 1.1.1i and below are affected by this issue. Users of these versions should upgrade to OpenSSL 1.1.1j. OpenSSL versions 1.0.2x and below are affected by this issue. However OpenSSL 1.0.2 is out of support and no longer receiving public updates. Premium support customers of OpenSSL 1.0.2 should upgrade to 1.0.2y. Other users should upgrade to 1.1.1j.

Found by Paul Kehrer.

• Fixed in OpenSSL 1.0.2y (premium support) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.1.1j

CVE-2021-23839 Incorrect SSLv2 rollback protection [Low severity] 16 February 2021:

OpenSSL 1.0.2 supports SSLv2. If a client attempts to negotiate SSLv2 with a server that is configured to support both SSLv2 and more recent SSL and TLS versions then a check is made for a version rollback attack when unpadding an RSA signature. Clients that support SSL or TLS versions greater than SSLv2 are supposed to use a special form of padding. A server that supports greater than SSLv2 is supposed to reject connection attempts from a client where this special form of padding is present, because this indicates that a version rollback has occurred (i.e. both client and server support greater than SSLv2, and yet this is the version that is being requested). The implementation of this padding check inverted the logic so that the connection attempt is accepted if the padding is present, and rejected if it is absent. This means that such as server will accept a connection if a version rollback attack has occurred. Further the server will erroneously reject a connection if a normal SSLv2 connection attempt is made. Only OpenSSL 1.0.2 servers from version 1.0.2s to 1.0.2x are affected by this issue. In order to be vulnerable a 1.0.2 server must: 1) have configured SSLv2 support at compile time (this is off by default), 2) have configured SSLv2 support at runtime (this is off by default), 3) have configured SSLv2 ciphersuites (these are not in the default ciphersuite list) OpenSSL 1.1.1 does not have SSLv2 support and therefore is not vulnerable to this issue. The underlying error is in the implementation of the RSA_padding_check_SSLv23() function. This also affects the RSA_SSLV23_PADDING padding mode used by various other functions. Although 1.1.1 does not support SSLv2 the RSA_padding_check_SSLv23() function still exists, as does the RSA_SSLV23_PADDING padding mode. Applications that directly call that function or use that padding mode will encounter this issue. However since there is no support for the SSLv2 protocol in 1.1.1 this is considered a bug and not a security issue in that version. OpenSSL 1.0.2 is out of support and no longer receiving public updates. Premium support customers of OpenSSL 1.0.2 should upgrade to 1.0.2y. Other users should upgrade to 1.1.1j.

Found by D. Katz and Joel Luellwitz (Trustwave).

• Fixed in OpenSSL 1.0.2y (premium support) (Affected since 1.0.2s)

2020

CVE-2020-1971 EDIPARTYNAME NULL pointer dereference [High severity] 08 December 2020:

The X.509 GeneralName type is a generic type for representing different types of names. One of those name types is known as EDIPartyName. OpenSSL provides a function GENERAL_NAME_cmp which compares different instances of a GENERAL_NAME to see if they are equal or not. This function behaves incorrectly when both GENERAL_NAMEs contain an EDIPARTYNAME. A NULL pointer dereference and a crash may occur leading to a possible denial of service attack. OpenSSL itself uses the GENERAL_NAME_cmp function for two purposes: 1) Comparing CRL distribution point names between an available CRL and a CRL distribution point embedded in an X509 certificate 2) When verifying that a timestamp response token signer matches the timestamp authority name (exposed via the API functions TS_RESP_verify_response and TS_RESP_verify_token) If an attacker can control both items being compared then that attacker could trigger a crash. For example if the attacker can trick a client or server into checking a malicious certificate against a malicious CRL then this may occur. Note that some applications automatically download CRLs based on a URL embedded in a certificate. This checking happens prior to the signatures on the certificate and CRL being verified. OpenSSL's s_server, s_client and verify tools have support for the "-crl_download" option which implements automatic CRL downloading and this attack has been demonstrated to work against those tools. Note that an unrelated bug means that affected versions of OpenSSL cannot parse or construct correct encodings of EDIPARTYNAME. However it is possible to construct a malformed EDIPARTYNAME that OpenSSL's parser will accept and hence trigger this attack. All OpenSSL 1.1.1 and 1.0.2 versions are affected by this issue. Other OpenSSL releases are out of support and have not been checked.

Found by David Benjamin (Google).

• Fixed in OpenSSL 1.0.2x (premium support) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.1.1i

CVE-2020-1968 Raccoon attack [Low severity] 09 September 2020:

The Raccoon attack exploits a flaw in the TLS specification which can lead to an attacker being able to compute the pre-master secret in connections which have used a Diffie-Hellman (DH) based ciphersuite. In such a case this would result in the attacker being able to eavesdrop on all encrypted communications sent over that TLS connection. The attack can only be exploited if an implementation re-uses a DH secret across multiple TLS connections. Note that this issue only impacts DH ciphersuites and not ECDH ciphersuites. This issue affects OpenSSL 1.0.2 which is out of support and no longer receiving public updates. OpenSSL 1.1.1 is not vulnerable to this issue.

Found by Robert Merget, Marcus Brinkmann, Nimrod Aviram, and Juraj Somorovsky.

• Fixed in OpenSSL 1.0.2w (premium support) (Affected since 1.0.2)

2019

CVE-2019-1551 rsaz_512_sqr overflow bug on x86_64 [Low severity] 06 December 2019:

There is an overflow bug in the x64_64 Montgomery squaring procedure used in exponentiation with 512-bit moduli. No EC algorithms are affected. Analysis suggests that attacks against 2-prime RSA1024, 3-prime RSA1536, and DSA1024 as a result of this defect would be very difficult to perform and are not believed likely. Attacks against DH512 are considered just feasible. However, for an attack the target would have to re-use the DH512 private key, which is not recommended anyway. Also applications directly using the low level API BN_mod_exp may be affected if they use BN_FLG_CONSTTIME.

Found by OSS-Fuzz and Guido Vranken.

• Fixed in OpenSSL 1.0.2u (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.1.1e

CVE-2019-1563 Padding Oracle in PKCS7_dataDecode and CMS_decrypt_set1_pkey [Low severity] 10 September 2019:

In situations where an attacker receives automated notification of the success or failure of a decryption attempt an attacker, after sending a very large number of messages to be decrypted, can recover a CMS/PKCS7 transported encryption key or decrypt any RSA encrypted message that was encrypted with the public RSA key, using a Bleichenbacher padding oracle attack. Applications are not affected if they use a certificate together with the private RSA key to the CMS_decrypt or PKCS7_decrypt functions to select the correct recipient info to decrypt.

Found by Bernd Edlinger.

• Fixed in OpenSSL 1.0.2t (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.1.1d, OpenSSL 1.1.0l

CVE-2019-1547 ECDSA remote timing attack [Low severity] 10 September 2019:

Normally in OpenSSL EC groups always have a co-factor present and this is used in side channel resistant code paths. However, in some cases, it is possible to construct a group using explicit parameters (instead of using a named curve). In those cases it is possible that such a group does not have the cofactor present. This can occur even where all the parameters match a known named curve. If such a curve is used then OpenSSL falls back to non-side channel resistant code paths which may result in full key recovery during an ECDSA signature operation. In order to be vulnerable an attacker would have to have the ability to time the creation of a large number of signatures where explicit parameters with no co-factor present are in use by an application using libcrypto. For the avoidance of doubt libssl is not vulnerable because explicit parameters are never used.

Found by Cesar Pereida García, Sohaib ul Hassan, Nicola Tuveri, Iaroslav Gridin, Alejandro Cabrera Aldaya, and Billy Brumley.

• Fixed in OpenSSL 1.0.2t (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.1.1d, OpenSSL 1.1.0l

CVE-2019-1552 Windows builds with insecure path defaults [Low severity] 30 July 2019:

OpenSSL has internal defaults for a directory tree where it can find a configuration file as well as certificates used for verification in TLS. This directory is most commonly referred to as OPENSSLDIR, and is configurable with the --prefix / --openssldir configuration options. For OpenSSL versions 1.1.0 and 1.1.1, the mingw configuration targets assume that resulting programs and libraries are installed in a Unix-like environment and the default prefix for program installation as well as for OPENSSLDIR should be '/usr/local'. However, mingw programs are Windows programs, and as such, find themselves looking at sub-directories of 'C:/usr/local', which may be world writable, which enables untrusted users to modify OpenSSL's default configuration, insert CA certificates, modify (or even replace) existing engine modules, etc. For OpenSSL 1.0.2, '/usr/local/ssl' is used as default for OPENSSLDIR on all Unix and Windows targets, including Visual C builds. However, some build instructions for the diverse Windows targets on 1.0.2 encourage you to specify your own --prefix. OpenSSL versions 1.1.1, 1.1.0 and 1.0.2 are affected by this issue. Due to the limited scope of affected deployments this has been assessed as low severity and therefore we are not creating new releases at this time.

Found by Rich Mirch.

• Fixed in OpenSSL 1.0.2t (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.1.1d, OpenSSL 1.1.0l

CVE-2019-1559 0-byte record padding oracle [Moderate severity] 26 February 2019:

If an application encounters a fatal protocol error and then calls SSL_shutdown() twice (once to send a close_notify, and once to receive one) then OpenSSL can respond differently to the calling application if a 0 byte record is received with invalid padding compared to if a 0 byte record is received with an invalid MAC. If the application then behaves differently based on that in a way that is detectable to the remote peer, then this amounts to a padding oracle that could be used to decrypt data. In order for this to be exploitable "non-stitched" ciphersuites must be in use. Stitched ciphersuites are optimised implementations of certain commonly used ciphersuites. Also the application must call SSL_shutdown() twice even if a protocol error has occurred (applications should not do this but some do anyway). AEAD ciphersuites are not impacted.

Found by Juraj Somorovsky, Robert Merget and Nimrod Aviram, with additional investigation by Steven Collison and Andrew Hourselt.

• Fixed in OpenSSL 1.0.2r (git commit) (Affected since 1.0.2)

2018

CVE-2018-5407 Microarchitecture timing vulnerability in ECC scalar multiplication [Low severity] 02 November 2018:

OpenSSL ECC scalar multiplication, used in e.g. ECDSA and ECDH, has been shown to be vulnerable to a microarchitecture timing side channel attack. An attacker with sufficient access to mount local timing attacks during ECDSA signature generation could recover the private key.

Found by Alejandro Cabrera Aldaya, Billy Brumley, Sohaib ul Hassan, Cesar Pereida Garcia and Nicola Tuveri.

• Fixed in OpenSSL 1.0.2q (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.1.0i

CVE-2018-0734 Timing attack against DSA [Low severity] 30 October 2018:

The OpenSSL DSA signature algorithm has been shown to be vulnerable to a timing side channel attack. An attacker could use variations in the signing algorithm to recover the private key.

Found by Samuel Weiser.

• Fixed in OpenSSL 1.0.2q (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.1.1a, OpenSSL 1.1.0j

CVE-2018-0732 Client DoS due to large DH parameter [Low severity] 12 June 2018:

During key agreement in a TLS handshake using a DH(E) based ciphersuite a malicious server can send a very large prime value to the client. This will cause the client to spend an unreasonably long period of time generating a key for this prime resulting in a hang until the client has finished. This could be exploited in a Denial Of Service attack.

Found by Guido Vranken.

• Fixed in OpenSSL 1.0.2p (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.1.0i

CVE-2018-0737 Cache timing vulnerability in RSA Key Generation [Low severity] 16 April 2018:

The OpenSSL RSA Key generation algorithm has been shown to be vulnerable to a cache timing side channel attack. An attacker with sufficient access to mount cache timing attacks during the RSA key generation process could recover the private key.

Found by Alejandro Cabrera Aldaya, Billy Brumley, Cesar Pereida Garcia and Luis Manuel Alvarez Tapia.

• Fixed in OpenSSL 1.0.2p (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.1.0i

CVE-2018-0739 Constructed ASN.1 types with a recursive definition could exceed the stack [Moderate severity] 27 March 2018:

Constructed ASN.1 types with a recursive definition (such as can be found in PKCS7) could eventually exceed the stack given malicious input with excessive recursion. This could result in a Denial Of Service attack. There are no such structures used within SSL/TLS that come from untrusted sources so this is considered safe.

Found by OSS-fuzz.

• Fixed in OpenSSL 1.0.2o (git commit) (Affected since 1.0.2b)
• This issue was also addressed in OpenSSL 1.1.0h

2017

CVE-2017-3738 bn_sqrx8x_internal carry bug on x86_64 [Low severity] 07 December 2017:

There is an overflow bug in the AVX2 Montgomery multiplication procedure used in exponentiation with 1024-bit moduli. No EC algorithms are affected. Analysis suggests that attacks against RSA and DSA as a result of this defect would be very difficult to perform and are not believed likely. Attacks against DH1024 are considered just feasible, because most of the work necessary to deduce information about a private key may be performed offline. The amount of resources required for such an attack would be significant. However, for an attack on TLS to be meaningful, the server would have to share the DH1024 private key among multiple clients, which is no longer an option since CVE-2016-0701. This only affects processors that support the AVX2 but not ADX extensions like Intel Haswell (4th generation). Note: The impact from this issue is similar to CVE-2017-3736, CVE-2017-3732 and CVE-2015-3193. Due to the low severity of this issue we are not issuing a new release of OpenSSL 1.1.0 at this time. The fix will be included in OpenSSL 1.1.0h when it becomes available. The fix is also available in commit e502cc86d in the OpenSSL git repository.

Found by David Benjamin (Google)/Google OSS-Fuzz.

• Fixed in OpenSSL 1.0.2n (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.1.0h

CVE-2017-3737 Read/write after SSL object in error state [Moderate severity] 07 December 2017:

OpenSSL 1.0.2 (starting from version 1.0.2b) introduced an "error state" mechanism. The intent was that if a fatal error occurred during a handshake then OpenSSL would move into the error state and would immediately fail if you attempted to continue the handshake. This works as designed for the explicit handshake functions (SSL_do_handshake(), SSL_accept() and SSL_connect()), however due to a bug it does not work correctly if SSL_read() or SSL_write() is called directly. In that scenario, if the handshake fails then a fatal error will be returned in the initial function call. If SSL_read()/SSL_write() is subsequently called by the application for the same SSL object then it will succeed and the data is passed without being decrypted/encrypted directly from the SSL/TLS record layer. In order to exploit this issue an application bug would have to be present that resulted in a call to SSL_read()/SSL_write() being issued after having already received a fatal error.

Found by David Benjamin (Google).

• Fixed in OpenSSL 1.0.2n (git commit) (Affected since 1.0.2b)

CVE-2017-3736 bn_sqrx8x_internal carry bug on x86_64 [Moderate severity] 02 November 2017:

There is a carry propagating bug in the x86_64 Montgomery squaring procedure. No EC algorithms are affected. Analysis suggests that attacks against RSA and DSA as a result of this defect would be very difficult to perform and are not believed likely. Attacks against DH are considered just feasible (although very difficult) because most of the work necessary to deduce information about a private key may be performed offline. The amount of resources required for such an attack would be very significant and likely only accessible to a limited number of attackers. An attacker would additionally need online access to an unpatched system using the target private key in a scenario with persistent DH parameters and a private key that is shared between multiple clients. This only affects processors that support the BMI1, BMI2 and ADX extensions like Intel Broadwell (5th generation) and later or AMD Ryzen.

Found by Google OSS-Fuzz.

• Fixed in OpenSSL 1.0.2m (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.1.0g

CVE-2017-3735 Possible Overread in parsing X.509 IPAdressFamily [Low severity] 28 August 2017:

While parsing an IPAdressFamily extension in an X.509 certificate, it is possible to do a one-byte overread. This would result in an incorrect text display of the certificate.

Found by Google OSS-Fuzz.

• Fixed in OpenSSL 1.0.2m (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.1.0g

CVE-2017-3732 BN_mod_exp may produce incorrect results on x86_64 [Moderate severity] 26 January 2017:

There is a carry propagating bug in the x86_64 Montgomery squaring procedure. No EC algorithms are affected. Analysis suggests that attacks against RSA and DSA as a result of this defect would be very difficult to perform and are not believed likely. Attacks against DH are considered just feasible (although very difficult) because most of the work necessary to deduce information about a private key may be performed offline. The amount of resources required for such an attack would be very significant and likely only accessible to a limited number of attackers. An attacker would additionally need online access to an unpatched system using the target private key in a scenario with persistent DH parameters and a private key that is shared between multiple clients. For example this can occur by default in OpenSSL DHE based SSL/TLS ciphersuites. Note: This issue is very similar to CVE-2015-3193 but must be treated as a separate problem.

Found by OSS-Fuzz project.

• Fixed in OpenSSL 1.0.2k (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.1.0d

CVE-2017-3731 Truncated packet could crash via OOB read [Moderate severity] 26 January 2017:

If an SSL/TLS server or client is running on a 32-bit host, and a specific cipher is being used, then a truncated packet can cause that server or client to perform an out-of-bounds read, usually resulting in a crash. For OpenSSL 1.1.0, the crash can be triggered when using CHACHA20/POLY1305; users should upgrade to 1.1.0d. For Openssl 1.0.2, the crash can be triggered when using RC4-MD5; users who have not disabled that algorithm should update to 1.0.2k.

Found by Robert Święcki of Google.

• Fixed in OpenSSL 1.0.2k (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.1.0d

2016

CVE-2016-7055 Montgomery multiplication may produce incorrect results [Low severity] 10 November 2016:

There is a carry propagating bug in the Broadwell-specific Montgomery multiplication procedure that handles input lengths divisible by, but longer than 256 bits. Analysis suggests that attacks against RSA, DSA and DH private keys are impossible. This is because the subroutine in question is not used in operations with the private key itself and an input of the attacker's direct choice. Otherwise the bug can manifest itself as transient authentication and key negotiation failures or reproducible erroneous outcome of public-key operations with specially crafted input. Among EC algorithms only Brainpool P-512 curves are affected and one presumably can attack ECDH key negotiation. Impact was not analyzed in detail, because pre-requisites for attack are considered unlikely. Namely multiple clients have to choose the curve in question and the server has to share the private key among them, neither of which is default behaviour. Even then only clients that chose the curve will be affected.

Found by Publicly reported.

• Fixed in OpenSSL 1.0.2k (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.1.0c

CVE-2016-7052 Missing CRL sanity check [Moderate severity] 26 September 2016:

This issue only affects OpenSSL 1.0.2i, released on 22nd September 2016. A bug fix which included a CRL sanity check was added to OpenSSL 1.1.0 but was omitted from OpenSSL 1.0.2i. As a result any attempt to use CRLs in OpenSSL 1.0.2i will crash with a null pointer exception.

Found by Bruce Stephens and Thomas Jakobi.

• Fixed in OpenSSL 1.0.2j (git commit) (Affected since 1.0.2i)

CVE-2016-6304 (OpenSSL Advisory) [High severity] 22 September 2016:

A malicious client can send an excessively large OCSP Status Request extension. If that client continually requests renegotiation, sending a large OCSP Status Request extension each time, then there will be unbounded memory growth on the server. This will eventually lead to a Denial Of Service attack through memory exhaustion. Servers with a default configuration are vulnerable even if they do not support OCSP. Builds using the "no-ocsp" build time option are not affected. Servers using OpenSSL versions prior to 1.0.1g are not vulnerable in a default configuration, instead only if an application explicitly enables OCSP stapling support.

Found by Shi Lei (Gear Team, Qihoo 360 Inc.).

• Fixed in OpenSSL 1.0.2i (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1u, OpenSSL 1.1.0a

CVE-2016-6306 (OpenSSL Advisory) [Low severity] 21 September 2016:

In OpenSSL 1.0.2 and earlier some missing message length checks can result in OOB reads of up to 2 bytes beyond an allocated buffer. There is a theoretical DoS risk but this has not been observed in practice on common platforms. The messages affected are client certificate, client certificate request and server certificate. As a result the attack can only be performed against a client or a server which enables client authentication.

Found by Shi Lei (Gear Team, Qihoo 360 Inc.).

• Fixed in OpenSSL 1.0.2i (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1u

CVE-2016-6303 (OpenSSL Advisory) [Low severity] 24 August 2016:

An overflow can occur in MDC2_Update() either if called directly or through the EVP_DigestUpdate() function using MDC2. If an attacker is able to supply very large amounts of input data after a previous call to EVP_EncryptUpdate() with a partial block then a length check can overflow resulting in a heap corruption. The amount of data needed is comparable to SIZE_MAX which is impractical on most platforms.

Found by Shi Lei (Gear Team, Qihoo 360 Inc.).

• Fixed in OpenSSL 1.0.2i (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1u

CVE-2016-2183 SWEET32 attack on Triple-DES [Low severity] 24 August 2016:

Because DES (and triple-DES) has only a 64-bit block size, birthday attacks are a real concern. For example, with the ability to run Javascript in a browser, it is possible to send enough traffic to cause a collision, and then use that information to recover something like a session Cookie. Triple-DES, which shows up as “DES-CBC3” in an OpenSSL cipher string, is still used on the Web, and major browsers are not yet willing to completely disable it. If you run a server, you should disable triple-DES. This is generally a configuration issue. If you run an old server that doesn’t support any better ciphers than DES or RC4, you should upgrade. For 1.0.2 and 1.0.1, we removed the triple-DES ciphers from the “HIGH” keyword and put them into “MEDIUM.” Note that we did not remove them from the “DEFAULT” keyword. For the 1.1.0 release, we treat triple-DES just like we are treating RC4. It is not compiled by default; you have to use “enable-weak-ssl-ciphers” as a config option. Even when those ciphers are compiled, triple-DES is only in the “MEDIUM” keyword. In addition we also removed it from the “DEFAULT” keyword.

Found by Karthik Bhargavan and Gaetan Leurent from Inria.

• Fixed in OpenSSL 1.0.2i (Affected since 1.0.2)

CVE-2016-6302 (OpenSSL Advisory) [Low severity] 23 August 2016:

If a server uses SHA512 for TLS session ticket HMAC it is vulnerable to a DoS attack where a malformed ticket will result in an OOB read which will ultimately crash. The use of SHA512 in TLS session tickets is comparatively rare as it requires a custom server callback and ticket lookup mechanism.

Found by Shi Lei (Gear Team, Qihoo 360 Inc.).

• Fixed in OpenSSL 1.0.2i (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1u

CVE-2016-2179 (OpenSSL Advisory) [Low severity] 22 August 2016:

In a DTLS connection where handshake messages are delivered out-of-order those messages that OpenSSL is not yet ready to process will be buffered for later use. Under certain circumstances, a flaw in the logic means that those messages do not get removed from the buffer even though the handshake has been completed. An attacker could force up to approx. 15 messages to remain in the buffer when they are no longer required. These messages will be cleared when the DTLS connection is closed. The default maximum size for a message is 100k. Therefore the attacker could force an additional 1500k to be consumed per connection. By opening many simulataneous connections an attacker could cause a DoS attack through memory exhaustion.

Found by Quan Luo.

• Fixed in OpenSSL 1.0.2i (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1u

CVE-2016-2181 (OpenSSL Advisory) [Low severity] 19 August 2016:

A flaw in the DTLS replay attack protection mechanism means that records that arrive for future epochs update the replay protection "window" before the MAC for the record has been validated. This could be exploited by an attacker by sending a record for the next epoch (which does not have to decrypt or have a valid MAC), with a very large sequence number. This means that all subsequent legitimate packets are dropped causing a denial of service for a specific DTLS connection.

Found by OCAP audit team.

• Fixed in OpenSSL 1.0.2i (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1u

CVE-2016-2182 (OpenSSL Advisory) [Low severity] 16 August 2016:

The function BN_bn2dec() does not check the return value of BN_div_word(). This can cause an OOB write if an application uses this function with an overly large BIGNUM. This could be a problem if an overly large certificate or CRL is printed out from an untrusted source. TLS is not affected because record limits will reject an oversized certificate before it is parsed.

Found by Shi Lei (Gear Team, Qihoo 360 Inc.).

• Fixed in OpenSSL 1.0.2i (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1u

CVE-2016-2180 (OpenSSL Advisory) [Low severity] 22 July 2016:

The function TS_OBJ_print_bio() misuses OBJ_obj2txt(): the return value is the total length the OID text representation would use and not the amount of data written. This will result in OOB reads when large OIDs are presented.

Found by Shi Lei (Gear Team, Qihoo 360 Inc.).

• Fixed in OpenSSL 1.0.2i (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1u

CVE-2016-2178 (OpenSSL Advisory) [Low severity] 07 June 2016:

Operations in the DSA signing algorithm should run in constant time in order to avoid side channel attacks. A flaw in the OpenSSL DSA implementation means that a non-constant time codepath is followed for certain operations. This has been demonstrated through a cache-timing attack to be sufficient for an attacker to recover the private DSA key.

Found by César Pereida (Aalto University), Billy Brumley (Tampere University of Technology), and Yuval Yarom (The University of Adelaide and NICTA).

• Fixed in OpenSSL 1.0.2i (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1u

CVE-2016-2177 (OpenSSL Advisory) [Low severity] 01 June 2016:

Avoid some undefined pointer arithmetic A common idiom in the codebase is to check limits in the following manner: "p + len > limit" Where "p" points to some malloc'd data of SIZE bytes and limit == p + SIZE "len" here could be from some externally supplied data (e.g. from a TLS message). The rules of C pointer arithmetic are such that "p + len" is only well defined where len <= SIZE. Therefore the above idiom is actually undefined behaviour. For example this could cause problems if some malloc implementation provides an address for "p" such that "p + len" actually overflows for values of len that are too big and therefore p + len < limit.

Found by Guido Vranken.

• Fixed in OpenSSL 1.0.2i (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1u

CVE-2016-2176 (OpenSSL Advisory) [Low severity] 03 May 2016:

ASN1 Strings that are over 1024 bytes can cause an overread in applications using the X509_NAME_oneline() function on EBCDIC systems. This could result in arbitrary stack data being returned in the buffer.

Found by Guido Vranken.

• Fixed in OpenSSL 1.0.2h (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1t

CVE-2016-2109 (OpenSSL Advisory) [Low severity] 03 May 2016:

When ASN.1 data is read from a BIO using functions such as d2i_CMS_bio() a short invalid encoding can casuse allocation of large amounts of memory potentially consuming excessive resources or exhausting memory. Any application parsing untrusted data through d2i BIO functions is affected. The memory based functions such as d2i_X509() are *not* affected. Since the memory based functions are used by the TLS library, TLS applications are not affected.

Found by Brian Carpenter.

• Fixed in OpenSSL 1.0.2h (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1t

CVE-2016-2108 (OpenSSL Advisory) [High severity] 03 May 2016:

This issue affected versions of OpenSSL prior to April 2015. The bug causing the vulnerability was fixed on April 18th 2015, and released as part of the June 11th 2015 security releases. The security impact of the bug was not known at the time. In previous versions of OpenSSL, ASN.1 encoding the value zero represented as a negative integer can cause a buffer underflow with an out-of-bounds write in i2c_ASN1_INTEGER. The ASN.1 parser does not normally create "negative zeroes" when parsing ASN.1 input, and therefore, an attacker cannot trigger this bug. However, a second, independent bug revealed that the ASN.1 parser (specifically, d2i_ASN1_TYPE) can misinterpret a large universal tag as a negative zero value. Large universal tags are not present in any common ASN.1 structures (such as X509) but are accepted as part of ANY structures. Therefore, if an application deserializes untrusted ASN.1 structures containing an ANY field, and later reserializes them, an attacker may be able to trigger an out-of-bounds write. This has been shown to cause memory corruption that is potentially exploitable with some malloc implementations. Applications that parse and re-encode X509 certificates are known to be vulnerable. Applications that verify RSA signatures on X509 certificates may also be vulnerable; however, only certificates with valid signatures trigger ASN.1 re-encoding and hence the bug. Specifically, since OpenSSL's default TLS X509 chain verification code verifies the certificate chain from root to leaf, TLS handshakes could only be targeted with valid certificates issued by trusted Certification Authorities.

Found by Huzaifa Sidhpurwala (Red Hat), Hanno Böck, David Benjamin (Google).

• Fixed in OpenSSL 1.0.2c (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1o

CVE-2016-2107 (OpenSSL Advisory) [High severity] 03 May 2016:

A MITM attacker can use a padding oracle attack to decrypt traffic when the connection uses an AES CBC cipher and the server support AES-NI. This issue was introduced as part of the fix for Lucky 13 padding attack (CVE-2013-0169). The padding check was rewritten to be in constant time by making sure that always the same bytes are read and compared against either the MAC or padding bytes. But it no longer checked that there was enough data to have both the MAC and padding bytes.

Found by Juraj Somorovsky.

• Fixed in OpenSSL 1.0.2h (git commit) (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1t

CVE-2016-2106 (OpenSSL Advisory) [Low severity] 03 May 2016:

An overflow can occur in the EVP_EncryptUpdate() function. If an attacker is able to supply very large amounts of input data after a previous call to EVP_EncryptUpdate() with a partial block then a length check can overflow resulting in a heap corruption. Following an analysis of all OpenSSL internal usage of the EVP_EncryptUpdate() function all usage is one of two forms. The first form is where the EVP_EncryptUpdate() call is known to be the first called function after an EVP_EncryptInit(), and therefore that specific call must be safe. The second form is where the length passed to EVP_EncryptUpdate() can be seen from the code to be some small value and therefore there is no possibility of an overflow. Since all instances are one of these two forms, it is believed that there can be no overflows in internal code due to this problem. It should be noted that EVP_DecryptUpdate() can call EVP_EncryptUpdate() in certain code paths. Also EVP_CipherUpdate() is a synonym for EVP_EncryptUpdate(). All instances of these calls have also been analysed too and it is believed there are no instances in internal usage where an overflow could occur. This could still represent a security issue for end user code that calls this function directly.

Found by Guido Vranken.

• Fixed in OpenSSL 1.0.2h (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1t

CVE-2016-2105 (OpenSSL Advisory) [Low severity] 03 May 2016:

An overflow can occur in the EVP_EncodeUpdate() function which is used for Base64 encoding of binary data. If an attacker is able to supply very large amounts of input data then a length check can overflow resulting in a heap corruption. Internally to OpenSSL the EVP_EncodeUpdate() function is primarly used by the PEM_write_bio* family of functions. These are mainly used within the OpenSSL command line applications. These internal uses are not considered vulnerable because all calls are bounded with length checks so no overflow is possible. User applications that call these APIs directly with large amounts of untrusted data may be vulnerable. (Note: Initial analysis suggested that the PEM_write_bio* were vulnerable, and this is reflected in the patch commit message. This is no longer believed to be the case).

Found by Guido Vranken.

• Fixed in OpenSSL 1.0.2h (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1t

CVE-2016-0800 (OpenSSL Advisory) [High severity] 01 March 2016:

A cross-protocol attack was discovered that could lead to decryption of TLS sessions by using a server supporting SSLv2 and EXPORT cipher suites as a Bleichenbacher RSA padding oracle. Note that traffic between clients and non-vulnerable servers can be decrypted provided another server supporting SSLv2 and EXPORT ciphers (even with a different protocol such as SMTP, IMAP or POP) shares the RSA keys of the non-vulnerable server. This vulnerability is known as DROWN (CVE-2016-0800). Recovering one session key requires the attacker to perform approximately 2^50 computation, as well as thousands of connections to the affected server. A more efficient variant of the DROWN attack exists against unpatched OpenSSL servers using versions that predate 1.0.2a, 1.0.1m, 1.0.0r and 0.9.8zf released on 19/Mar/2015 (see CVE-2016-0703 below). Users can avoid this issue by disabling the SSLv2 protocol in all their SSL/TLS servers, if they've not done so already. Disabling all SSLv2 ciphers is also sufficient, provided the patches for CVE-2015-3197 (fixed in OpenSSL 1.0.1r and 1.0.2f) have been deployed. Servers that have not disabled the SSLv2 protocol, and are not patched for CVE-2015-3197 are vulnerable to DROWN even if all SSLv2 ciphers are nominally disabled, because malicious clients can force the use of SSLv2 with EXPORT ciphers. OpenSSL 1.0.2g and 1.0.1s deploy the following mitigation against DROWN: SSLv2 is now by default disabled at build-time. Builds that are not configured with "enable-ssl2" will not support SSLv2. Even if "enable-ssl2" is used, users who want to negotiate SSLv2 via the version-flexible SSLv23_method() will need to explicitly call either of: SSL_CTX_clear_options(ctx, SSL_OP_NO_SSLv2); or SSL_clear_options(ssl, SSL_OP_NO_SSLv2); as appropriate. Even if either of those is used, or the application explicitly uses the version-specific SSLv2_method() or its client or server variants, SSLv2 ciphers vulnerable to exhaustive search key recovery have been removed. Specifically, the SSLv2 40-bit EXPORT ciphers, and SSLv2 56-bit DES are no longer available. In addition, weak ciphers in SSLv3 and up are now disabled in default builds of OpenSSL. Builds that are not configured with "enable-weak-ssl-ciphers" will not provide any "EXPORT" or "LOW" strength ciphers.

Found by Nimrod Aviram and Sebastian Schinzel.

• Fixed in OpenSSL 1.0.2g (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1s

CVE-2016-0799 (OpenSSL Advisory) [Low severity] 01 March 2016:

The internal |fmtstr| function used in processing a "%s" format string in the BIO_*printf functions could overflow while calculating the length of a string and cause an OOB read when printing very long strings. Additionally the internal |doapr_outch| function can attempt to write to an OOB memory location (at an offset from the NULL pointer) in the event of a memory allocation failure. In 1.0.2 and below this could be caused where the size of a buffer to be allocated is greater than INT_MAX. E.g. this could be in processing a very long "%s" format string. Memory leaks can also occur. The first issue may mask the second issue dependent on compiler behaviour. These problems could enable attacks where large amounts of untrusted data is passed to the BIO_*printf functions. If applications use these functions in this way then they could be vulnerable. OpenSSL itself uses these functions when printing out human-readable dumps of ASN.1 data. Therefore applications that print this data could be vulnerable if the data is from untrusted sources. OpenSSL command line applications could also be vulnerable where they print out ASN.1 data, or if untrusted data is passed as command line arguments. Libssl is not considered directly vulnerable. Additionally certificates etc received via remote connections via libssl are also unlikely to be able to trigger these issues because of message size limits enforced within libssl.

Found by Guido Vranken.

• Fixed in OpenSSL 1.0.2g (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1s

CVE-2016-0798 (OpenSSL Advisory) [Low severity] 01 March 2016:

The SRP user database lookup method SRP_VBASE_get_by_user had confusing memory management semantics; the returned pointer was sometimes newly allocated, and sometimes owned by the callee. The calling code has no way of distinguishing these two cases. Specifically, SRP servers that configure a secret seed to hide valid login information are vulnerable to a memory leak: an attacker connecting with an invalid username can cause a memory leak of around 300 bytes per connection. Servers that do not configure SRP, or configure SRP but do not configure a seed are not vulnerable. In Apache, the seed directive is known as SSLSRPUnknownUserSeed. To mitigate the memory leak, the seed handling in SRP_VBASE_get_by_user is now disabled even if the user has configured a seed. Applications are advised to migrate to SRP_VBASE_get1_by_user. However, note that OpenSSL makes no strong guarantees about the indistinguishability of valid and invalid logins. In particular, computations are currently not carried out in constant time.

Found by Emilia Käsper (OpenSSL).

• Fixed in OpenSSL 1.0.2g (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1s

CVE-2016-0797 (OpenSSL Advisory) [Low severity] 01 March 2016:

In the BN_hex2bn function the number of hex digits is calculated using an int value |i|. Later |bn_expand| is called with a value of |i * 4|. For large values of |i| this can result in |bn_expand| not allocating any memory because |i * 4| is negative. This can leave the internal BIGNUM data field as NULL leading to a subsequent NULL ptr deref. For very large values of |i|, the calculation |i * 4| could be a positive value smaller than |i|. In this case memory is allocated to the internal BIGNUM data field, but it is insufficiently sized leading to heap corruption. A similar issue exists in BN_dec2bn. This could have security consequences if BN_hex2bn/BN_dec2bn is ever called by user applications with very large untrusted hex/dec data. This is anticipated to be a rare occurrence. All OpenSSL internal usage of these functions use data that is not expected to be untrusted, e.g. config file data or application command line arguments. If user developed applications generate config file data based on untrusted data then it is possible that this could also lead to security consequences. This is also anticipated to be rare.

Found by Guido Vranken.

• Fixed in OpenSSL 1.0.2g (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1s

CVE-2016-0705 (OpenSSL Advisory) [Low severity] 01 March 2016:

A double free bug was discovered when OpenSSL parses malformed DSA private keys and could lead to a DoS attack or memory corruption for applications that receive DSA private keys from untrusted sources. This scenario is considered rare.

Found by Adam Langley (Google/BoringSSL).

• Fixed in OpenSSL 1.0.2g (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1s

CVE-2016-0704 (OpenSSL Advisory) [Moderate severity] 01 March 2016:

This issue only affected versions of OpenSSL prior to March 19th 2015 at which time the code was refactored to address the vulnerability CVE-2015-0293. s2_srvr.c overwrite the wrong bytes in the master-key when applying Bleichenbacher protection for export cipher suites. This provides a Bleichenbacher oracle, and could potentially allow more efficient variants of the DROWN attack.

Found by David Adrian and J.Alex Halderman (University of Michigan).

• Fixed in OpenSSL 1.0.2a (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 0.9.8zf, OpenSSL 1.0.0r, OpenSSL 1.0.1m

CVE-2016-0703 (OpenSSL Advisory) [High severity] 01 March 2016:

This issue only affected versions of OpenSSL prior to March 19th 2015 at which time the code was refactored to address vulnerability CVE-2015-0293. s2_srvr.c did not enforce that clear-key-length is 0 for non-export ciphers. If clear-key bytes are present for these ciphers, they *displace* encrypted-key bytes. This leads to an efficient divide-and-conquer key recovery attack: if an eavesdropper has intercepted an SSLv2 handshake, they can use the server as an oracle to determine the SSLv2 master-key, using only 16 connections to the server and negligible computation. More importantly, this leads to a more efficient version of DROWN that is effective against non-export ciphersuites, and requires no significant computation.

Found by David Adrian and J.Alex Halderman (University of Michigan).

• Fixed in OpenSSL 1.0.2a (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 0.9.8zf, OpenSSL 1.0.0r, OpenSSL 1.0.1m

CVE-2016-0702 (OpenSSL Advisory) [Low severity] 01 March 2016:

A side-channel attack was found which makes use of cache-bank conflicts on the Intel Sandy-Bridge microarchitecture which could lead to the recovery of RSA keys. The ability to exploit this issue is limited as it relies on an attacker who has control of code in a thread running on the same hyper-threaded core as the victim thread which is performing decryptions.

Found by Yuval Yarom, The University of Adelaide and NICTA, Daniel Genkin, Technion and Tel Aviv University, and Nadia Heninger, University of Pennsylvania.

• Fixed in OpenSSL 1.0.2g (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1s

CVE-2016-0701 (OpenSSL Advisory) [High severity] 28 January 2016:

Historically OpenSSL usually only ever generated DH parameters based on "safe" primes. More recently (in version 1.0.2) support was provided for generating X9.42 style parameter files such as those required for RFC 5114 support. The primes used in such files may not be "safe". Where an application is using DH configured with parameters based on primes that are not "safe" then an attacker could use this fact to find a peer's private DH exponent. This attack requires that the attacker complete multiple handshakes in which the peer uses the same private DH exponent. For example this could be used to discover a TLS server's private DH exponent if it's reusing the private DH exponent or it's using a static DH ciphersuite. OpenSSL provides the option SSL_OP_SINGLE_DH_USE for ephemeral DH (DHE) in TLS. It is not on by default. If the option is not set then the server reuses the same private DH exponent for the life of the server process and would be vulnerable to this attack. It is believed that many popular applications do set this option and would therefore not be at risk. OpenSSL before 1.0.2f will reuse the key if: - SSL_CTX_set_tmp_dh()/SSL_set_tmp_dh() is used and SSL_OP_SINGLE_DH_USE is not set. - SSL_CTX_set_tmp_dh_callback()/SSL_set_tmp_dh_callback() is used, and both the parameters and the key are set and SSL_OP_SINGLE_DH_USE is not used. This is an undocumted feature and parameter files don't contain the key. - Static DH ciphersuites are used. The key is part of the certificate and so it will always reuse it. This is only supported in 1.0.2. It will not reuse the key for DHE ciphers suites if: - SSL_OP_SINGLE_DH_USE is set - SSL_CTX_set_tmp_dh_callback()/SSL_set_tmp_dh_callback() is used and the callback does not provide the key, only the parameters. The callback is almost always used like this. Non-safe primes are generated by OpenSSL when using: - genpkey with the dh_rfc5114 option. This will write an X9.42 style file including the prime-order subgroup size "q". This is supported since the 1.0.2 version. Older versions can't read files generated in this way. - dhparam with the -dsaparam option. This has always been documented as requiring the single use. The fix for this issue adds an additional check where a "q" parameter is available (as is the case in X9.42 based parameters). This detects the only known attack, and is the only possible defense for static DH ciphersuites. This could have some performance impact. Additionally the SSL_OP_SINGLE_DH_USE option has been switched on by default and cannot be disabled. This could have some performance impact.

Found by Antonio Sanso (Adobe).

• Fixed in OpenSSL 1.0.2f (Affected since 1.0.2)

CVE-2015-3197 (OpenSSL Advisory) [Low severity] 28 January 2016:

A malicious client can negotiate SSLv2 ciphers that have been disabled on the server and complete SSLv2 handshakes even if all SSLv2 ciphers have been disabled, provided that the SSLv2 protocol was not also disabled via SSL_OP_NO_SSLv2.

Found by Nimrod Aviram and Sebastian Schinzel.

• Fixed in OpenSSL 1.0.2f (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1r

2015

CVE-2015-3196 (OpenSSL Advisory) [Low severity] 03 December 2015:

If PSK identity hints are received by a multi-threaded client then the values are wrongly updated in the parent SSL_CTX structure. This can result in a race condition potentially leading to a double free of the identify hint data.

Found by Stephen Henson (OpenSSL).

• Fixed in OpenSSL 1.0.2d (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1p, OpenSSL 1.0.0t

CVE-2015-3195 (OpenSSL Advisory) [Moderate severity] 03 December 2015:

When presented with a malformed X509_ATTRIBUTE structure OpenSSL will leak memory. This structure is used by the PKCS#7 and CMS routines so any application which reads PKCS#7 or CMS data from untrusted sources is affected. SSL/TLS is not affected.

Found by Adam Langley (Google/BoringSSL) using libFuzzer.

• Fixed in OpenSSL 1.0.2e (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1q, OpenSSL 1.0.0t, OpenSSL 0.9.8zh

CVE-2015-3194 (OpenSSL Advisory) [Moderate severity] 03 December 2015:

The signature verification routines will crash with a NULL pointer dereference if presented with an ASN.1 signature using the RSA PSS algorithm and absent mask generation function parameter. Since these routines are used to verify certificate signature algorithms this can be used to crash any certificate verification operation and exploited in a DoS attack. Any application which performs certificate verification is vulnerable including OpenSSL clients and servers which enable client authentication.

Found by Loïc Jonas Etienne (Qnective AG).

• Fixed in OpenSSL 1.0.2e (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1q

CVE-2015-3193 (OpenSSL Advisory) [Moderate severity] 03 December 2015:

There is a carry propagating bug in the x86_64 Montgomery squaring procedure. No EC algorithms are affected. Analysis suggests that attacks against RSA and DSA as a result of this defect would be very difficult to perform and are not believed likely. Attacks against DH are considered just feasible (although very difficult) because most of the work necessary to deduce information about a private key may be performed offline. The amount of resources required for such an attack would be very significant and likely only accessible to a limited number of attackers. An attacker would additionally need online access to an unpatched system using the target private key in a scenario with persistent DH parameters and a private key that is shared between multiple clients. For example this can occur by default in OpenSSL DHE based SSL/TLS ciphersuites.

Found by Hanno Böck.

• Fixed in OpenSSL 1.0.2e (Affected since 1.0.2)

CVE-2015-1794 (OpenSSL Advisory) [Low severity] 11 August 2015:

If a client receives a ServerKeyExchange for an anonymous DH ciphersuite with the value of p set to 0 then a seg fault can occur leading to a possible denial of service attack.

Found by Guy Leaver (Cisco).

• Fixed in OpenSSL 1.0.2e (Affected since 1.0.2)

CVE-2015-1793 (OpenSSL Advisory) [High severity] 09 July 2015:

An error in the implementation of the alternative certificate chain logic could allow an attacker to cause certain checks on untrusted certificates to be bypassed, such as the CA flag, enabling them to use a valid leaf certificate to act as a CA and "issue" an invalid certificate.

Found by Adam Langley and David Benjamin (Google/BoringSSL).

• Fixed in OpenSSL 1.0.2d (Affected since 1.0.2b)
• This issue was also addressed in OpenSSL 1.0.1p

CVE-2015-1792 (OpenSSL Advisory) [Moderate severity] 11 June 2015:

When verifying a signedData message the CMS code can enter an infinite loop if presented with an unknown hash function OID. This can be used to perform denial of service against any system which verifies signedData messages using the CMS code.

Found by Johannes Bauer.

• Fixed in OpenSSL 1.0.2b (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1n, OpenSSL 1.0.0s, OpenSSL 0.9.8zg

CVE-2015-1790 (OpenSSL Advisory) [Moderate severity] 11 June 2015:

The PKCS#7 parsing code does not handle missing inner EncryptedContent correctly. An attacker can craft malformed ASN.1-encoded PKCS#7 blobs with missing content and trigger a NULL pointer dereference on parsing. Applications that decrypt PKCS#7 data or otherwise parse PKCS#7 structures from untrusted sources are affected. OpenSSL clients and servers are not affected.

Found by Michal Zalewski (Google).

• Fixed in OpenSSL 1.0.2b (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1n, OpenSSL 1.0.0s, OpenSSL 0.9.8zg

CVE-2015-1789 (OpenSSL Advisory) [Moderate severity] 11 June 2015:

X509_cmp_time does not properly check the length of the ASN1_TIME string and can read a few bytes out of bounds. In addition, X509_cmp_time accepts an arbitrary number of fractional seconds in the time string. An attacker can use this to craft malformed certificates and CRLs of various sizes and potentially cause a segmentation fault, resulting in a DoS on applications that verify certificates or CRLs. TLS clients that verify CRLs are affected. TLS clients and servers with client authentication enabled may be affected if they use custom verification callbacks.

Found by Robert Święcki (Google Security Team). Found by Hanno Böck.

• Fixed in OpenSSL 1.0.2b (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1n, OpenSSL 1.0.0s, OpenSSL 0.9.8zg

CVE-2015-1788 (OpenSSL Advisory) [Moderate severity] 11 June 2015:

When processing an ECParameters structure OpenSSL enters an infinite loop if the curve specified is over a specially malformed binary polynomial field. This can be used to perform denial of service against any system which processes public keys, certificate requests or certificates. This includes TLS clients and TLS servers with client authentication enabled.

Found by Joseph Birr-Pixton.

• Fixed in OpenSSL 1.0.2b (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1n, OpenSSL 1.0.0e, OpenSSL 0.9.8s

CVE-2015-1791 (OpenSSL Advisory) [Low severity] 02 June 2015:

If a NewSessionTicket is received by a multi-threaded client when attempting to reuse a previous ticket then a race condition can occur potentially leading to a double free of the ticket data.

Found by Emilia Käsper (OpenSSL).

• Fixed in OpenSSL 1.0.2b (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1n, OpenSSL 1.0.0s, OpenSSL 0.9.8zg

CVE-2015-1787 (OpenSSL Advisory) [Moderate severity] 19 March 2015:

Empty CKE with client auth and DHE. If client auth is used then a server can seg fault in the event of a DHE ciphersuite being selected and a zero length ClientKeyExchange message being sent by the client. This could be exploited in a DoS attack.

Found by Matt Caswell (OpenSSL development team).

• Fixed in OpenSSL 1.0.2a (Affected since 1.0.2)

CVE-2015-0293 (OpenSSL Advisory) [Moderate severity] 19 March 2015:

DoS via reachable assert in SSLv2 servers. A malicious client can trigger an OPENSSL_assert in servers that both support SSLv2 and enable export cipher suites by sending a specially crafted SSLv2 CLIENT-MASTER-KEY message.

Found by Sean Burford (Google) and Emilia Käsper (OpenSSL development team).

• Fixed in OpenSSL 1.0.2a (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1m, OpenSSL 1.0.0r, OpenSSL 0.9.8zf

CVE-2015-0291 (OpenSSL Advisory) [High severity] 19 March 2015:

ClientHello sigalgs DoS. If a client connects to an OpenSSL 1.0.2 server and renegotiates with an invalid signature algorithms extension a NULL pointer dereference will occur. This can be exploited in a DoS attack against the server.

Found by David Ramos (Stanford University).

• Fixed in OpenSSL 1.0.2a (Affected since 1.0.2)

CVE-2015-0290 (OpenSSL Advisory) [Moderate severity] 19 March 2015:

Multiblock corrupted pointer. OpenSSL 1.0.2 introduced the "multiblock" performance improvement. This feature only applies on 64 bit x86 architecture platforms that support AES NI instructions. A defect in the implementation of "multiblock" can cause OpenSSL's internal write buffer to become incorrectly set to NULL when using non-blocking IO. Typically, when the user application is using a socket BIO for writing, this will only result in a failed connection. However if some other BIO is used then it is likely that a segmentation fault will be triggered, thus enabling a potential DoS attack.

Found by Daniel Danner and Rainer Mueller.

• Fixed in OpenSSL 1.0.2a (Affected since 1.0.2)

CVE-2015-0289 (OpenSSL Advisory) [Moderate severity] 19 March 2015:

PKCS#7 NULL pointer dereference. The PKCS#7 parsing code does not handle missing outer ContentInfo correctly. An attacker can craft malformed ASN.1-encoded PKCS#7 blobs with missing content and trigger a NULL pointer dereference on parsing. Applications that verify PKCS#7 signatures, decrypt PKCS#7 data or otherwise parse PKCS#7 structures from untrusted sources are affected. OpenSSL clients and servers are not affected.

Found by Michal Zalewski (Google).

• Fixed in OpenSSL 1.0.2a (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1m, OpenSSL 1.0.0r, OpenSSL 0.9.8zf

CVE-2015-0287 (OpenSSL Advisory) [Moderate severity] 19 March 2015:

ASN.1 structure reuse memory corruption. Reusing a structure in ASN.1 parsing may allow an attacker to cause memory corruption via an invalid write. Such reuse is and has been strongly discouraged and is believed to be rare.

Found by Emilia Käsper (OpenSSL development team).

• Fixed in OpenSSL 1.0.2a (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1m, OpenSSL 1.0.0r, OpenSSL 0.9.8zf

CVE-2015-0286 (OpenSSL Advisory) [Moderate severity] 19 March 2015:

Segmentation fault in ASN1_TYPE_cmp. The function ASN1_TYPE_cmp will crash with an invalid read if an attempt is made to compare ASN.1 boolean types. Since ASN1_TYPE_cmp is used to check certificate signature algorithm consistency this can be used to crash any certificate verification operation and exploited in a DoS attack. Any application which performs certificate verification is vulnerable including OpenSSL clients and servers which enable client authentication.

Found by Stephen Henson (OpenSSL development team).

• Fixed in OpenSSL 1.0.2a (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1m, OpenSSL 1.0.0r, OpenSSL 0.9.8zf

CVE-2015-0209 (OpenSSL Advisory) [Low severity] 19 March 2015:

Use After Free following d2i_ECPrivatekey error. A malformed EC private key file consumed via the d2i_ECPrivateKey function could cause a use after free condition. This, in turn, could cause a double free in several private key parsing functions (such as d2i_PrivateKey or EVP_PKCS82PKEY) and could lead to a DoS attack or memory corruption for applications that receive EC private keys from untrusted sources. This scenario is considered rare.

Found by The BoringSSL project.

• Fixed in OpenSSL 1.0.2a (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1m, OpenSSL 1.0.0r, OpenSSL 0.9.8zf

CVE-2015-0208 (OpenSSL Advisory) [Moderate severity] 19 March 2015:

Segmentation fault for invalid PSS parameters. The signature verification routines will crash with a NULL pointer dereference if presented with an ASN.1 signature using the RSA PSS algorithm and invalid parameters. Since these routines are used to verify certificate signature algorithms this can be used to crash any certificate verification operation and exploited in a DoS attack. Any application which performs certificate verification is vulnerable including OpenSSL clients and servers which enable client authentication.

Found by Brian Carpenter.

• Fixed in OpenSSL 1.0.2a (Affected since 1.0.2)

CVE-2015-0207 (OpenSSL Advisory) [Moderate severity] 19 March 2015:

Segmentation fault in DTLSv1_listen. A defect in the implementation of DTLSv1_listen means that state is preserved in the SSL object from one invocation to the next that can lead to a segmentation fault. Errors processing the initial ClientHello can trigger this scenario. An example of such an error could be that a DTLS1.0 only client is attempting to connect to a DTLS1.2 only server.

Found by Per Allansson.

• Fixed in OpenSSL 1.0.2a (Affected since 1.0.2)

CVE-2015-0285 (OpenSSL Advisory) [Low severity] 10 March 2015:

Under certain conditions an OpenSSL 1.0.2 client can complete a handshake with an unseeded PRNG. If the handshake succeeds then the client random that has been used will have been generated from a PRNG with insufficient entropy and therefore the output may be predictable.

Found by Matt Caswell (OpenSSL development team).

• Fixed in OpenSSL 1.0.2a (Affected since 1.0.2)

CVE-2015-0288 (OpenSSL Advisory) [Low severity] 02 March 2015:

X509_to_X509_REQ NULL pointer deref. The function X509_to_X509_REQ will crash with a NULL pointer dereference if the certificate key is invalid. This function is rarely used in practice.

Found by Brian Carpenter.

• Fixed in OpenSSL 1.0.2a (Affected since 1.0.2)
• This issue was also addressed in OpenSSL 1.0.1m, OpenSSL 1.0.0r, OpenSSL 0.9.8zf