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.
Exploitability
AV:NAC:MAu:NImpact
C:PI:PA:N5.8/AV:N/AC:M/Au:N/C:P/I:P/A:N