The gnutls_x509_crt_get_serial function in the GnuTLS library before 1.2.1, when running on big-endian, 64-bit platforms, calls the asn1_read_value with a pointer to the wrong data type and the wrong length value, which allows remote attackers to bypass the certificate revocation list (CRL) check and cause a stack-based buffer overflow via a crafted X.509 certificate, related to extraction of a serial number.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A9759
http://www.vupen.com/english/advisories/2010/1054
http://www.vupen.com/english/advisories/2010/0713
http://www.securityfocus.com/bid/38959
http://www.redhat.com/support/errata/RHSA-2010-0167.html
http://www.mandriva.com/security/advisories?name=MDVSA-2010:089
http://secunia.com/advisories/39127
http://lists.opensuse.org/opensuse-security-announce/2010-08/msg00001.html