lib/x509/verify.c in GnuTLS before 3.1.22 and 3.2.x before 3.2.12 does not properly handle unspecified errors when verifying X.509 certificates from SSL servers, which allows man-in-the-middle attackers to spoof servers via a crafted certificate. http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2014-0092