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Medium 5.9
Timing Oracle in RSA Decryption
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 …
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High 7.5CVE-2022-4450 EPSS 29%
Double free after calling PEM_read_bio_ex
The function PEM_read_bio_ex() reads a PEM file from a BIO and parses and decodes the "name" (e.g. "CERTIFICATE"), any header data and the payload data. If the function succeeds then the "name_out", "header" and "data" arguments are populated with pointers to…
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High 7.5
Use-after-free following BIO_new_NDEF
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.…
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High 7.5
Invalid pointer dereference in d2i_PKCS7 functions
An invalid pointer dereference on read can be triggered when an application tries to load malformed PKCS7 data with the d2i_PKCS7(), d2i_PKCS7_bio() or d2i_PKCS7_fp() functions. The result of the dereference is an application crash which could lead to a denia…
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High 7.5
NULL dereference validating DSA public key
An invalid pointer dereference on read can be triggered when an application tries to check a malformed DSA public key by the EVP_PKEY_public_check() function. This will most likely lead to an application crash. This function can be called on public keys suppl…
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High 7.4
X.400 address type confusion in X.509 GeneralName
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 fiel…
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High 7.5
NULL dereference during PKCS7 data verification
A NULL pointer can be dereferenced when signatures are being verified on PKCS7 signed or signedAndEnveloped data. In case the hash algorithm used for the signature is known to the OpenSSL library but the implementation of the hash algorithm is not available t…
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High 7.5
X.509 Policy Constraints Double Locking
If an X.509 certificate contains a malformed policy constraint and policy processing is enabled, then a write lock will be taken twice recursively. On some operating systems (most widely: Windows) this results in a denial of service when the affected process …
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High 7.5
X.509 Email Address 4-byte Buffer Overflow
A buffer overrun can be triggered in X.509 certificate verification, specifically in name constraint checking. Note that this occurs after certificate chain signature verification and requires either a CA to have signed the malicious certificate or for the ap…
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High 7.5
X.509 Email Address Variable Length Buffer Overflow
A buffer overrun can be triggered in X.509 certificate verification, specifically in name constraint checking. Note that this occurs after certificate chain signature verification and requires either a CA to have signed a malicious certificate or for an appli…
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High 7.5CVE-2022-3358 Public exploit
Using a Custom Cipher with NID_undef may lead to NULL encryption
OpenSSL supports creating a custom cipher via the legacy EVP_CIPHER_meth_new() function and associated function calls. This function was deprecated in OpenSSL 3.0 and application authors are instead encouraged to use the new provider mechanism in order to imp…
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High 7.5CVE-2022-2097 Public exploit
AES OCB fails to encrypt some bytes
AES OCB mode for 32-bit x86 platforms using the AES-NI assembly optimised implementation will not encrypt the entirety of the data under some circumstances. This could reveal sixteen bytes of data that was preexisting in the memory that wasn't written. In the…
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High 7.5
Resource leakage when decoding certificates and keys
The OPENSSL_LH_flush() function, which empties a hash table, contains a bug that breaks reuse of the memory occuppied by the removed hash table entries. This function is used when decoding certificates or keys. If a long lived process periodically decodes cer…
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Medium 5.9
Incorrect MAC key used in the RC4-MD5 ciphersuite
The OpenSSL 3.0 implementation of the RC4-MD5 ciphersuite incorrectly uses the AAD data as the MAC key. This makes the MAC key trivially predictable. An attacker could exploit this issue by performing a man-in-the-middle attack to modify data being sent from …
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Medium 5.3
OCSP_basic_verify may incorrectly verify the response signing certificate
The function `OCSP_basic_verify` verifies the signer certificate on an OCSP response. In the case where the (non-default) flag OCSP_NOCHECKS is used then the response will be positive (meaning a successful verification) even in the case where the response sig…
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High 7.5
Infinite loop in BN_mod_sqrt() reachable when parsing certificates
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 e…
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High 7.5
Invalid handling of X509_verify_cert() internal errors in libssl
Internally libssl in OpenSSL calls X509_verify_cert() on the client side to verify a certificate supplied by a server. That function may return a negative return value to indicate an internal error (for example out of memory). Such a negative return value is …
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High 7.4
Read buffer overruns processing ASN.1 strings
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 dat…
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Critical 9.8
SM2 Decryption Buffer Overflow
In order to decrypt SM2 encrypted data an application is expected to call the API function EVP_PKEY_decrypt(). Typically an application will call this function twice. The first time, on entry, the "out" parameter can be NULL and, on exit, the "outlen" paramet…
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High 7.4
CA certificate check bypass with X509_V_FLAG_X509_STRICT
The X509_V_FLAG_X509_STRICT flag enables additional security checks of the certificates present in a certificate chain. It is not set by default. Starting from OpenSSL version 1.1.1h a check to disallow certificates in the chain that have explicitly encoded e…
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Medium 5.9
NULL pointer deref in signature_algorithms processing
An OpenSSL TLS server may crash if sent a maliciously crafted renegotiation ClientHello message from a client. If a TLSv1.2 renegotiation ClientHello omits the signature_algorithms extension (where it was present in the initial ClientHello), but includes a si…
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High 7.5
Integer overflow in CipherUpdate
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 …
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Medium 5.9CVE-2021-23841 Public exploit
Null pointer deref in X509_issuer_and_serial_hash()
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 …
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Unscored —
Incorrect SSLv2 rollback protection
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 …
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Medium 5.9CVE-2020-1971 Public exploit
EDIPARTYNAME NULL pointer dereference
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 equa…
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High 7.5
Segmentation fault in SSL_check_chain
Server or client applications that call the SSL_check_chain() function during or after a TLS 1.3 handshake may crash due to a NULL pointer dereference as a result of incorrect handling of the "signature_algorithms_cert" TLS extension. The crash occurs if an i…
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Unscored —CVE-2019-1551 EPSS 14%
rsaz_512_sqr overflow bug on x86_64
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 wou…
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Unscored —
ECDSA remote timing attack
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 p…
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Unscored —
Fork Protection
OpenSSL 1.1.1 introduced a rewritten random number generator (RNG). This was intended to include protection in the event of a fork() system call in order to ensure that the parent and child processes did not share the same RNG state. However this protection w…
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Unscored —
Padding Oracle in PKCS7_dataDecode and CMS_decrypt_set1_pkey
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…
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Unscored —
ChaCha20-Poly1305 with long nonces
ChaCha20-Poly1305 is an AEAD cipher, and requires a unique nonce input for every encryption operation. RFC 7539 specifies that the nonce value (IV) should be 96 bits (12 bytes). OpenSSL allows a variable nonce length and front pads the nonce with 0 bytes if i…
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Unscored —CVE-2019-1559 EPSS 17%
0-byte record padding oracle
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 …
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Unscored —CVE-2018-5407 Public exploit
Simultaneous Multi-threading (SMT) in processors can enable local users to exploit software vulnerable to timing attack…
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Unscored —CVE-2018-0734 EPSS 12%
Timing attack against DSA
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. Fixed in OpenSSL 1.1.1a (Affected 1.1.1). Fixed in OpenSSL 1.1.0j (Affec…
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Unscored —
Timing attack against ECDSA signature generation
The OpenSSL ECDSA 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. Fixed in OpenSSL 1.1.0j (Affected 1.1.0-1.1.0i). Fixed in OpenSSL 1.1.…
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Unscored —CVE-2018-0732 EPSS 47%
Client DoS due to large DH parameter
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 …
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Unscored —CVE-2018-0737 EPSS 12%
Cache timing vulnerability in RSA Key Generation
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. Fixed in Open…
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Unscored —
Incorrect CRYPTO_memcmp on HP-UX PA-RISC
Because of an implementation bug the PA-RISC CRYPTO_memcmp function is effectively reduced to only comparing the least significant bit of each byte. This allows an attacker to forge messages that would be considered as authenticated in an amount of tries lowe…
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Unscored —CVE-2018-0739 EPSS 19%
Constructed ASN.1 types with a recursive definition could exceed the stack
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…
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Unscored —CVE-2017-3738 EPSS 13%
There is an overflow bug in the AVX2 Montgomery multiplication procedure used in exponentiation with 1024-bit moduli. N…