An OS Command Injection vulnerability exists in Moodle’s TeX filter administrative configuration due to insufficient sanitization of input parameters processed by external utilities such as ImageMagick. A site administrator could supply crafted input that results in execution of arbitrary operating system commands. Successful exploitation allows full compromise of the Moodle server, including unauthorized access to data and service disruption. This issue affects sites where the TeX notation filter is enabled and ImageMagick is present.