Vulnerability in OpenSSL CVE-2008-5077

The Google Security Team discovered several functions inside OpenSSL incorrectly checked the result after calling the EVP_VerifyFinal function, allowing a malformed signature to be treated as a good signature rather than as an error. This issue affected the signature checks on DSA and ECDSA keys used with SSL/TLS. One way to exploit this flaw would be for a remote attacker who is in control of a malicious server or who can use a 'man in the middle' attack to present a malformed SSL/TLS signature from a certificate chain to a vulnerable client, bypassing validation.