Cross-site request forgery (CSRF) vulnerability in markposts.php in Moodle 3.0 through 3.0.3, 2.9 through 2.9.5, 2.8 through 2.8.11, 2.7 through 2.7.13 and earlier allows remote attackers to hijack the authentication of users for requests that marks forum posts as read.
https://bugzilla.redhat.com/show_bug.cgi?id=1335933
http://www.securitytracker.com/id/1035902
http://www.securityfocus.com/bid/91281
http://www.openwall.com/lists/oss-security/2016/05/17/4
http://git.moodle.org/gw?p=moodle.git&a=search&h=HEAD&st=commit&s=MDL-53755