Executive brief
Chamilo LMS, a popular open-source learning management system, contains a critical security flaw in its file management system. An attacker with teacher-level permissions can execute malicious commands on the underlying server, potentially leading to a full system takeover. This could result in the theft of sensitive student data, modification of grades, or the installation of ransomware.
Technical details
An OS command injection vulnerability exists in Chamilo LMS prior to versions 1.11.38 and 2.0.0-RC.3. The root cause is the improper neutralization of user-controlled input in the move() function within fileManage.lib.php, which passes path values directly to exec() shell commands without using escapeshellarg(). An attacker can exploit this by uploading a directory with shell metacharacters in its name (e.g., via the Course Backup Import feature) and then moving a document into that directory. This triggers the execution of arbitrary commands as the web server user (www-data). While the vulnerability requires authentication, Chamilo's default configuration allows any user to create courses and become a teacher, making the flaw widely accessible. The issue is resolved by implementing proper shell argument escaping or replacing shell-based file operations with native PHP functions.
Affected products
- Chamilo Chamilo LMS < 1.11.38, < 2.0.0-RC.3
Timeline
- 2026-04-10: disclosed
- 2026-04-10: advisory
- 2026-04-10: patched