Cross-site scripting (XSS) vulnerability in user/profile.php in Moodle through 2.3.11, 2.4.x before 2.4.11, 2.5.x before 2.5.7, 2.6.x before 2.6.4, and 2.7.x before 2.7.1 allows remote authenticated users to inject arbitrary web script or HTML via the Skype ID profile field.