Palo Alto Networks GlobalProtect before 1.1.7, and NetConnect, does not verify X.509 certificates from SSL servers, which allows man-in-the-middle attackers to spoof portal servers and obtain sensitive information via a crafted certificate.
https://security.paloaltonetworks.com/CVE-2012-6606
http://archives.neohapsis.com/archives/bugtraq/2012-10/0100.html