Cross-site request forgery (CSRF) vulnerability in mod/assign/adminmanageplugins.php in Moodle through 2.6.11, 2.7.x before 2.7.13, 2.8.x before 2.8.11, 2.9.x before 2.9.5, and 3.0.x before 3.0.3 allows remote attackers to hijack the authentication of administrators for requests that manage Assignment plugins.