python-cryptography: Duplicate self-signed intermediates can cause exponential path-building
python-cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. In versions 42.0.0 through 48.0.0, when resolving invalid certificate chains that include duplicate copies of self-signed certificates, the processing recursively invokes the same candidate, leading to an exponential blowup. Although the limitation that the chain depth cannot exceed a specified maximum depth prevents unbounded recursion and guarantees termination, an attacker-controlled certificate chain can lead the processing to easily take more than 5s to reject in testing. This amplification could form the basis for a resource ex
python-cryptography verifier accepts wildcard DNS names allowing escape from permittedSubtrees
cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. In versions 45.0.0 through 48.0.0, if an intermediate constrained CA permits the DNS name foo.example.com, and the leaf certificate has a wildcard in its DNS SAN of *.example.com, python-cryptography's verifier accepts which allows escaping outside of the permitted names. The core issue is in DNSConstraint::matches, where a wildcard pattern was treated as matching a more-specific permitted constraint even though *.example.com can expand to sibling names such as bar.example.com outside foo.example.com. This allows acceptance of an invalid ce
cryptography: PKCS#7 EnvelopedData decryption exposes a Bleichenbacher oracle through distinguishable errors and timing
cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. From 44.0.0 until 50.0.0, pkcs7_decrypt_der, pkcs7_decrypt_pem, and pkcs7_decrypt_smime reported the outcome of decrypting a RecipientInfo's encryptedKey in several distinguishable ways, one of which disclosed the exact length recovered from the RSA operation. The same distinction was also observable by timing. An application that decrypts attacker-supplied EnvelopedData and reflects the outcome gives the attacker a Bleichenbacher oracle against the content-encryption key. Decryption ran as RSA PKCS#1 v1.5 decrypt of encryptedKey, build an
Vulnerable OpenSSL included in cryptography wheels
pyca/cryptography's wheels include a statically linked copy of OpenSSL. The versions of OpenSSL included in wheels prior to cryptograph 48.01 are vulnerable to a security issue. More details about the vulnerability itself can be found in https://openssl-library.org/news/secadv/20260609.txt.
If you are building cryptography source ("sdist") then you are responsible for upgrading your copy of OpenSSL. Only users installing from wheels built by the cryptography project (i.e., those distributed on PyPI) need to update their cryptography versions.
cryptography has a buffer overflow if non-contiguous buffers were passed to APIs
cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. From 45.0.0 to before 46.0.7, if a non-contiguous buffer was passed to APIs which accepted Python buffers (e.g. Hash.update()), this could lead to buffer overflows. This vulnerability is fixed in 46.0.7.
cryptography has incomplete DNS name constraint enforcement on peer names
cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Prior to version 46.0.6, DNS name constraints were only validated against SANs within child certificates, and not the "peer name" presented during each validation. Consequently, cryptography would allow a peer named bar.example.com to validate against a wildcard leaf certificate for *.example.com, even if the leaf's parent certificate (or upwards) contained an excluded subtree constraint for bar.example.com. This issue has been patched in version 46.0.6.
cryptography Subgroup Attack Due to Missing Subgroup Validation for SECT Curves
cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Prior to 46.0.5, the public_key_from_numbers (or EllipticCurvePublicNumbers.public_key()), EllipticCurvePublicNumbers.public_key(), load_der_public_key() and load_pem_public_key() functions do not verify that the point belongs to the expected prime-order subgroup of the curve. This missing validation allows an attacker to provide a public key point P from a small-order subgroup. This can lead to security issues in various situations, such as the most commonly used signature verification (ECDSA) and shared key negotiation (ECDH). When the vi
RFC7250 handshakes with unauthenticated servers don't abort as expected
Issue summary: Clients using RFC7250 Raw Public Keys (RPKs) to authenticate a
server may fail to notice that the server was not authenticated, because
handshakes don't abort as expected when the SSL_VERIFY_PEER verification mode
is set.
Impact summary: TLS and DTLS connections using raw public keys may be
vulnerable to man-in-middle attacks when server authentication failure is not
detected by clients.
RPKs are disabled by default in both TLS clients and TLS servers. The issue
only arises when TLS clients explicitly enable RPK use by the server, and the
server, likewise, enables sending of an RPK instead of an X.509 certificate
chain. The
pyca/cryptography has a vulnerable OpenSSL included in cryptography wheels
pyca/cryptography's wheels include a statically linked copy of OpenSSL. The versions of OpenSSL included in cryptography 37.0.0-43.0.0 are vulnerable to a security issue. More details about the vulnerability itself can be found in https://openssl-library.org/news/secadv/20240903.txt.
If you are building cryptography source ("sdist") then you are responsible for upgrading your copy of OpenSSL. Only users installing from wheels built by the cryptography project (i.e., those distributed on PyPI) need to update their cryptography versions.
cryptography NULL pointer deference with pkcs12.serialize_key_and_certificates when called with a non-matching certificate and private key and an hmac_hash override
cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Starting in version 38.0.0 and prior to version 42.0.4, if `pkcs12.serialize_key_and_certificates` is called with both a certificate whose public key did not match the provided private key and an `encryption_algorithm` with `hmac_hash` set (via `PrivateFormat.PKCS12.encryption_builder().hmac_hash(...)`, then a NULL pointer dereference would occur, crashing the Python process. This has been resolved in version 42.0.4, the first version in which a `ValueError` is properly raised.
Python-cryptography: bleichenbacher timing oracle attack against rsa decryption - incomplete fix for cve-2020-25659
A flaw was found in the python-cryptography package. This issue may allow a remote attacker to decrypt captured messages in TLS servers that use RSA key exchanges, which may lead to exposure of confidential or sensitive data.
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 wi
cryptography vulnerable to NULL-dereference when loading PKCS7 certificates
cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. Calling `load_pem_pkcs7_certificates` or `load_der_pkcs7_certificates` could lead to a NULL-pointer dereference and segfault. Exploitation of this vulnerability poses a serious risk of Denial of Service (DoS) for any application attempting to deserialize a PKCS7 blob/certificate. The consequences extend to potential disruptions in system availability and stability. This vulnerability has been patched in version 41.0.6.
Vulnerable OpenSSL included in cryptography wheels
pyca/cryptography's wheels include a statically linked copy of OpenSSL. The versions of OpenSSL included in cryptography 2.5-41.0.3 are vulnerable to several security issues. More details about the vulnerabilities themselves can be found in https://www.openssl.org/news/secadv/20230908.txt.
If you are building cryptography source ("sdist") then you are responsible for upgrading your copy of OpenSSL. Only users installing from wheels built by the cryptography project (i.e., those distributed on PyPI) need to update their cryptography versions.
pyca/cryptography's wheels include vulnerable OpenSSL
pyca/cryptography's wheels include a statically linked copy of OpenSSL. The versions of OpenSSL included in cryptography 0.8-41.0.2 are vulnerable to several security issues. More details about the vulnerabilities themselves can be found in https://www.openssl.org/news/secadv/20230731.txt, https://www.openssl.org/news/secadv/20230719.txt, and https://www.openssl.org/news/secadv/20230714.txt.
If you are building cryptography source ("sdist") then you are responsible for upgrading your copy of OpenSSL. Only users installing from wheels built by the cryptography project (i.e., those distributed on PyPI) need to update their cryptography version
Vulnerable OpenSSL included in cryptography wheels
pyca/cryptography's wheels include a statically linked copy of OpenSSL. The versions of OpenSSL included in cryptography 0.5-40.0.2 are vulnerable to a security issue. More details about the vulnerability itself can be found in https://www.openssl.org/news/secadv/20230530.txt.
If you are building cryptography source ("sdist") then you are responsible for upgrading your copy of OpenSSL. Only users installing from wheels built by the cryptography project (i.e., those distributed on PyPI) need to update their cryptography versions.
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
Cipher.update_into can corrupt memory in pyca cryptography
cryptography is a package designed to expose cryptographic primitives and recipes to Python developers. In affected versions `Cipher.update_into` would accept Python objects which implement the buffer protocol, but provide only immutable buffers. This would allow immutable objects (such as `bytes`) to be mutated, thus violating fundamental rules of Python and resulting in corrupted output. This now correctly raises an exception. This issue has been present since `update_into` was originally introduced in cryptography 1.8.
Vulnerable OpenSSL included in cryptography wheels
pyca/cryptography's wheels include a statically linked copy of OpenSSL. The versions of OpenSSL included in cryptography 37.0.0-38.0.3 are vulnerable to a number of security issues. More details about the vulnerabilities themselves can be found in https://www.openssl.org/news/secadv/20221101.txt.
If you are building cryptography source ("sdist") then you are responsible for upgrading your copy of OpenSSL. Only users installing from wheels built by the cryptography project (i.e., those distributed on PyPI) need to update their cryptography versions.