OpenSSL

Cryptography and SSL/TLS Toolkit

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 3.1

Jump to year: 2024, 2023

2024

CVE-2024-4741 Use After Free with SSL_free_buffers [Low severity] 27 May 2024:
Issue summary: Calling the OpenSSL API function SSL_free_buffers may cause memory to be accessed that was previously freed in some situations
Impact summary: A use after free can have a range of potential consequences such as the corruption of valid data, crashes or execution of arbitrary code. However, only applications that directly call the SSL_free_buffers function are affected by this issue. Applications that do not call this function are not vulnerable. Our investigations indicate that this function is rarely used by applications.
The SSL_free_buffers function is used to free the internal OpenSSL buffer used when processing an incoming record from the network. The call is only expected to succeed if the buffer is not currently in use. However, two scenarios have been identified where the buffer is freed even when still in use.
The first scenario occurs where a record header has been received from the network and processed by OpenSSL, but the full record body has not yet arrived. In this case calling SSL_free_buffers will succeed even though a record has only been partially processed and the buffer is still in use.
The second scenario occurs where a full record containing application data has been received and processed by OpenSSL but the application has only read part of this data. Again a call to SSL_free_buffers will succeed even though the buffer is still in use.
While these scenarios could occur accidentally during normal operation a malicious attacker could attempt to engineer a stituation where this occurs. We are not aware of this issue being actively exploited.
The FIPS modules in 3.3, 3.2, 3.1 and 3.0 are not affected by this issue.
Found by William Ahern (Akamai). Fix developed by Matt Caswell. Fix developed by Watson Ladd (Akamai).
CVE-2024-4603 Excessive time spent checking DSA keys and parameters [Low severity] 16 May 2024:
Issue summary: Checking excessively long DSA keys or parameters may be very slow.
Impact summary: Applications that use the functions EVP_PKEY_param_check() or EVP_PKEY_public_check() to check a DSA public key or DSA 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 functions EVP_PKEY_param_check() or EVP_PKEY_public_check() perform various checks on DSA parameters. Some of those computations take a long time if the modulus (`p` parameter) is too large.
Trying to use a very large modulus is slow and OpenSSL will not allow using public keys with a modulus which is over 10,000 bits in length for signature verification. However the key and parameter check functions do not limit the modulus size when performing the checks.
An application that calls EVP_PKEY_param_check() or EVP_PKEY_public_check() and supplies a key or parameters obtained from an untrusted source could be vulnerable to a Denial of Service attack.
These functions are not called by OpenSSL itself on untrusted DSA keys so only applications that directly call these functions may be vulnerable.
Also vulnerable are the OpenSSL pkey 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 affected by this issue.
Found by OSS-Fuzz. Fix developed by Tomas Mraz.
CVE-2024-2511 Unbounded memory growth with session handling in TLSv1.3 [Low severity] 08 April 2024:
Issue summary: Some non-default TLS server configurations can cause unbounded memory growth when processing TLSv1.3 sessions
Impact summary: An attacker may exploit certain server configurations to trigger unbounded memory growth that would lead to a Denial of Service
This problem can occur in TLSv1.3 if the non-default SSL_OP_NO_TICKET option is being used (but not if early_data support is also configured and the default anti-replay protection is in use). In this case, under certain conditions, the session cache can get into an incorrect state and it will fail to flush properly as it fills. The session cache will continue to grow in an unbounded manner. A malicious client could deliberately create the scenario for this failure to force a Denial of Service. It may also happen by accident in normal operation.
This issue only affects TLS servers supporting TLSv1.3. It does not affect TLS clients.
The FIPS modules in 3.2, 3.1 and 3.0 are not affected by this issue. OpenSSL 1.0.2 is also not affected by this issue.
Found by Manish Patidar (Hewlett Packard Enterprise). Fix developed by Matt Caswell.
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.
CVE-2023-6237 Excessive time spent checking invalid RSA public keys [Low severity] 15 January 2024:
Issue summary: Checking excessively long invalid RSA public keys may take a long time.
Impact summary: Applications that use the function EVP_PKEY_public_check() to check RSA public keys may experience long delays. Where the key that is being checked has been obtained from an untrusted source this may lead to a Denial of Service.
When function EVP_PKEY_public_check() is called on RSA public keys, a computation is done to confirm that the RSA modulus, n, is composite. For valid RSA keys, n is a product of two or more large primes and this computation completes quickly. However, if n is an overly large prime, then this computation would take a long time.
An application that calls EVP_PKEY_public_check() and supplies an RSA key obtained from an untrusted source could be vulnerable to a Denial of Service attack.
The function EVP_PKEY_public_check() is not called from other OpenSSL functions however it is called from the OpenSSL pkey command line application. For that reason that application is also vulnerable if used with the '-pubin' and '-check' options on untrusted data.
The OpenSSL SSL/TLS implementation is not affected by this issue.
The OpenSSL 3.0 and 3.1 FIPS providers are affected by this issue.
Found by OSS-Fuzz. Fix developed by Tomas Mraz.
  • Fixed in OpenSSL 3.1.5 (git commit) (Affected since 3.1.0)
  • This issue was also addressed in OpenSSL 3.0.13, OpenSSL 3.2.1
CVE-2023-6129 POLY1305 MAC implementation corrupts vector registers on PowerPC [Low severity] 09 January 2024:
Issue summary: The POLY1305 MAC (message authentication code) implementation contains a bug that might corrupt the internal state of applications running on PowerPC CPU based platforms if the CPU provides vector instructions.
Impact summary: If an attacker can influence whether the POLY1305 MAC algorithm is used, the application state might be corrupted with various application dependent consequences.
The POLY1305 MAC (message authentication code) implementation in OpenSSL for PowerPC CPUs restores the contents of vector registers in a different order than they are saved. Thus the contents of some of these vector registers are corrupted when returning to the caller. The vulnerable code is used only on newer PowerPC processors supporting the PowerISA 2.07 instructions.
The consequences of this kind of internal application state corruption can be various - from no consequences, if the calling application does not depend on the contents of non-volatile XMM registers at all, to the worst consequences, where the attacker could get complete control of the application process. However unless the compiler uses the vector registers for storing pointers, the most likely consequence, if any, would be an incorrect result of some application dependent calculations or a crash leading to a denial of service.
The POLY1305 MAC algorithm is most frequently used as part of the CHACHA20-POLY1305 AEAD (authenticated encryption with associated data) algorithm. The most common usage of this AEAD cipher is with TLS protocol versions 1.2 and 1.3. If this cipher is enabled on the server a malicious client can influence whether this AEAD cipher is used. This implies that TLS server applications using OpenSSL can be potentially impacted. However we are currently not aware of any concrete application that would be affected by this issue therefore we consider this a Low severity security issue.
Found by Sverker Eriksson. Fix developed by Rohan McLure.
  • Fixed in OpenSSL 3.1.5 (git commit) (Affected since 3.1.0)
  • This issue was also addressed in OpenSSL 3.2.1, OpenSSL 3.0.13

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.
CVE-2023-5363 Incorrect cipher key & IV length processing [MODERATE severity] 24 October 2023:
Issue summary: A bug has been identified in the processing of key and initialisation vector (IV) lengths. This can lead to potential truncation or overruns during the initialisation of some symmetric ciphers.
Impact summary: A truncation in the IV can result in non-uniqueness, which could result in loss of confidentiality for some cipher modes.
When calling EVP_EncryptInit_ex2(), EVP_DecryptInit_ex2() or EVP_CipherInit_ex2() the provided OSSL_PARAM array is processed after the key and IV have been established. Any alterations to the key length, via the "keylen" parameter or the IV length, via the "ivlen" parameter, within the OSSL_PARAM array will not take effect as intended, potentially causing truncation or overreading of these values. The following ciphers and cipher modes are impacted: RC2, RC4, RC5, CCM, GCM and OCB.
For the CCM, GCM and OCB cipher modes, truncation of the IV can result in loss of confidentiality. For example, when following NIST's SP 800-38D section 8.2.1 guidance for constructing a deterministic IV for AES in GCM mode, truncation of the counter portion could lead to IV reuse.
Both truncations and overruns of the key and overruns of the IV will produce incorrect results and could, in some cases, trigger a memory exception. However, these issues are not currently assessed as security critical.
Changing the key and/or IV lengths is not considered to be a common operation and the vulnerable API was recently introduced. Furthermore it is likely that application developers will have spotted this problem during testing since decryption would fail unless both peers in the communication were similarly vulnerable. For these reasons we expect the probability of an application being vulnerable to this to be quite low. However if an application is vulnerable then this issue is considered very serious. For these reasons we have assessed this issue as Moderate severity overall.
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 because the issue lies outside of the FIPS provider boundary.
OpenSSL 3.1 and 3.0 are vulnerable to this issue.
Found by Tony Battersby (Cybernetics). Fix developed by Dr Paul Dale.
  • Fixed in OpenSSL 3.1.4 (git commit) (Affected since 3.1.0)
  • This issue was also addressed in OpenSSL 3.0.12
CVE-2023-4807 POLY1305 MAC implementation corrupts XMM registers on Windows [Low severity] 08 September 2023:
Issue summary: The POLY1305 MAC (message authentication code) implementation contains a bug that might corrupt the internal state of applications on the Windows 64 platform when running on newer X86_64 processors supporting the AVX512-IFMA instructions.
Impact summary: If in an application that uses the OpenSSL library an attacker can influence whether the POLY1305 MAC algorithm is used, the application state might be corrupted with various application dependent consequences.
The POLY1305 MAC (message authentication code) implementation in OpenSSL does not save the contents of non-volatile XMM registers on Windows 64 platform when calculating the MAC of data larger than 64 bytes. Before returning to the caller all the XMM registers are set to zero rather than restoring their previous content. The vulnerable code is used only on newer x86_64 processors supporting the AVX512-IFMA instructions.
The consequences of this kind of internal application state corruption can be various - from no consequences, if the calling application does not depend on the contents of non-volatile XMM registers at all, to the worst consequences, where the attacker could get complete control of the application process. However given the contents of the registers are just zeroized so the attacker cannot put arbitrary values inside, the most likely consequence, if any, would be an incorrect result of some application dependent calculations or a crash leading to a denial of service.
The POLY1305 MAC algorithm is most frequently used as part of the CHACHA20-POLY1305 AEAD (authenticated encryption with associated data) algorithm. The most common usage of this AEAD cipher is with TLS protocol versions 1.2 and 1.3 and a malicious client can influence whether this AEAD cipher is used by the server. This implies that server applications using OpenSSL can be potentially impacted. However we are currently not aware of any concrete application that would be affected by this issue therefore we consider this a Low severity security issue.
As a workaround the AVX512-IFMA instructions support can be disabled at runtime by setting the environment variable OPENSSL_ia32cap:
OPENSSL_ia32cap=:~0x200000
The FIPS provider is not affected by this issue.
Found by Zach Wilson. Fix developed by Bernd Edlinger.
  • Fixed in OpenSSL 3.1.3 (git commit) (Affected since 3.1.0)
  • This issue was also addressed in OpenSSL 3.0.11, OpenSSL 1.1.1w
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.
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.
CVE-2023-2975 AES-SIV implementation ignores empty associated data entries [Low severity] 07 July 2023:
Issue summary: The AES-SIV cipher implementation contains a bug that causes it to ignore empty associated data entries which are unauthenticated as a consequence.
Impact summary: Applications that use the AES-SIV algorithm and want to authenticate empty data entries as associated data can be misled by removing, adding or reordering such empty entries as these are ignored by the OpenSSL implementation. We are currently unaware of any such applications.
The AES-SIV algorithm allows for authentication of multiple associated data entries along with the encryption. To authenticate empty data the application has to call EVP_EncryptUpdate() (or EVP_CipherUpdate()) with NULL pointer as the output buffer and 0 as the input buffer length. The AES-SIV implementation in OpenSSL just returns success for such a call instead of performing the associated data authentication operation. The empty data thus will not be authenticated.
As this issue does not affect non-empty associated data authentication and we expect it to be rare for an application to use empty associated data entries this is qualified as Low severity issue.
Found by Juerg Wullschleger (Google). Fix developed by Tomas Mraz.
  • Fixed in OpenSSL 3.1.2 (git commit) (Affected since 3.1.0)
  • This issue was also addressed in OpenSSL 3.0.10
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.
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.
CVE-2023-1255 Input buffer over-read in AES-XTS implementation on 64 bit ARM [Low severity] 21 March 2023:
Issue summary: The AES-XTS cipher decryption implementation for 64 bit ARM platform contains a bug that could cause it to read past the input buffer, leading to a crash.
Impact summary: Applications that use the AES-XTS algorithm on the 64 bit ARM platform can crash in rare circumstances. The AES-XTS algorithm is usually used for disk encryption.
The AES-XTS cipher decryption implementation for 64 bit ARM platform will read past the end of the ciphertext buffer if the ciphertext size is 4 mod 5 in 16 byte blocks, e.g. 144 bytes or 1024 bytes. If the memory after the ciphertext buffer is unmapped, this will trigger a crash which results in a denial of service.
If an attacker can control the size and location of the ciphertext buffer being decrypted by an application using AES-XTS on 64 bit ARM, the application is affected. This is fairly unlikely making this issue a Low severity one.
Found by Anton Romanov (Amazon). Fix developed by Nevine Ebeid (Amazon).
  • Fixed in OpenSSL 3.1.1 (git commit) (Affected since 3.1.0)
  • This issue was also addressed in OpenSSL 3.0.9
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.
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.