Threats tagged 'ghsa-r854-jrxh-36qx'

phpseclib's SSH2 implementation uses a variable-time comparison for HMAC verification in the get_binary_packet() method by using PHP's != operator instead of the constant-time hash_equals(). This timing discrepancy (CWE-208) can theoretically leak information about the HMAC, but practical exploitation is mitigated by SSH's disconnect-on-MAC-failure behavior and per-connection session keys. The issue affects all supported branches and is fixed in versions 1.0.28, 2.0.53, and 3.0.51.