Release of unverified plaintext in the CCM (CcmBlockCipher) and DSTU 7624 CCM (KCcmBlockCipher) AEAD modes in Legion of the Bouncy Castle Inc. bc-csharp before 2.7.0 allows a remote attacker to obtain decryptions of ciphertexts of their choosing via forged messages sent to an application that lets the output buffer of a failed decryption be observed, for example through buffer reuse or logging, because decryption wrote the recovered plaintext into the caller-supplied output buffer before checking the authentication tag and left it there when the check failed. Only decryption into a caller-supplied buffer is affected; methods that return a newly allocated array are not.
Weakness
The product does not validate or incorrectly validates the integrity check values or “checksums” of a message. This may prevent it from detecting if the data has been modified or corrupted in transmission.
Potential Mitigations
Related Attack Patterns
- https://cwe.mitre.org/data/definitions/145.html
- https://cwe.mitre.org/data/definitions/463.html
- https://cwe.mitre.org/data/definitions/75.html