mnet/xmlrpc/client.php in MNET in Moodle 1.9.x before 1.9.14, 2.0.x before 2.0.5, and 2.1.x before 2.1.2 does not properly process the return value of the openssl_verify function, which allows remote attackers to bypass validation via a crafted certificate.
https://bugzilla.redhat.com/show_bug.cgi?id=747444
http://moodle.org/mod/forum/discuss.php?d=188314
http://git.moodle.org/gw?p=moodle.git%3Ba=commit%3Bh=54941685e3e86ec085641dcb7ebb1f96f06735b2