An issue was discovered in GLPI through 9.2.1. The application is affected by XSS in the query string to front/preference.php. An attacker is able to create a malicious URL that, if opened by an authenticated user with debug privilege, will execute JavaScript code supplied by the attacker. The attacker-supplied code can perform a wide variety of actions, such as stealing the victim's session token or login credentials, performing arbitrary actions on the victim's behalf, and logging their keystrokes.
https://membership.backbox.org/glpi-9-2-1-multiple-vulnerabilities/