M2Crypto does not properly check the return value from the OpenSSL EVP_VerifyFinal, DSA_verify, ECDSA_verify, DSA_do_verify, and ECDSA_do_verify functions, which might allow remote attackers to bypass validation of the certificate chain via a malformed SSL/TLS signature, a similar vulnerability to CVE-2008-5077. NOTE: a Linux vendor disputes the relevance of this report to the M2Crypto product because "these functions are not used anywhere in m2crypto.