CVSS8.1
Severityhigh
WeaknessCWE-347
ExploitedNot in CISA KEV
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
Description
Libreswan, via the function RSA_authenticate_hash_signature_raw_rsa(), did not correctly verify the length of the authentication hash when the SIG payload of an IKEv1 packet was encoded using PKCS #1 RSA Encryption as per RFC 2313. A remote attacker can use a variation on the Bleichenbacher attack to forge the SIG payload when small public exponents are being used (e.g., e=3), which could lead to impersonation. Additionally, a remote attacker, by encoding a shorter than expected hash in the SIG payload, could trigger an assertion leading to denial-of-service. The daemon aborts and restarts; continued exploitation causes sustained denial of service. Remote code execution is not possible. X.50