Multiple cross-site request forgery (CSRF) vulnerabilities in the Forum module in Moodle through 2.4.11, 2.5.x before 2.5.9, 2.6.x before 2.6.6, and 2.7.x before 2.7.3 allow remote attackers to hijack the authentication of arbitrary users for requests that set a tracking preference within (1) mod/forum/deprecatedlib.php, (2) mod/forum/forum.js, (3) mod/forum/index.php, or (4) mod/forum/lib.php.