USN-8087-1 fixed a vulnerability in python-cryptography. The update caused
a regression when using ECC algorithms with certain software. This update
fixes the problem.
We apologize for the inconvenience.
Original advisory details:
It was discovered that python-cryptography incorrectly handled subgroup
validation for SECT curves. A remote attacker could use this issue to
perform a subgroup attack and possibly recover the least significant bits
of private keys.
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
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.
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.
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.