6.5 Medium
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
UNCHANGED
Confidentiality Impact
NONE
Integrity Impact
LOW
Availability Impact
LOW
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
0.001 Low
EPSS
Percentile
29.1%
Previously, Cipher.update_into
would accept Python objects which implement the buffer protocol, but provide only immutable buffers:
>>> outbuf = b"\x00" * 32
>>> c = ciphers.Cipher(AES(b"\x00" * 32), modes.ECB()).encryptor()
>>> c.update_into(b"\x00" * 16, outbuf)
16
>>> outbuf
b'\xdc\x95\xc0x\xa2@\x89\x89\xadH\xa2\x14\x92\x84 \x87\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00'
This would allow immutable objects (such as bytes
) to be mutated, thus violating fundamental rules of Python. This is a soundness bug – it allows programmers to misuse an API, it cannot be exploited by attacker controlled data alone.
This now correctly raises an exception.
This issue has been present since update_into
was originally introduced in cryptography 1.8.
CPE | Name | Operator | Version |
---|---|---|---|
cryptography | eq | 2.2.1 | |
cryptography | eq | 38.0.1 | |
cryptography | eq | 2.0.2 | |
cryptography | eq | 3.4.3 | |
cryptography | eq | 2.1.3 | |
cryptography | eq | 2.6.1 | |
cryptography | eq | 2.3 | |
cryptography | eq | 38.0.2 | |
cryptography | eq | 2.5 | |
cryptography | eq | 2.9 |