Executive brief
ATutor is an open-source learning management system used to create and deliver online courses. A path traversal vulnerability in its ZIP file extraction functionality allows instructors to upload specially crafted archives that extract files outside the intended directory, enabling them to place executable code in the web root and gain complete control of the server.
Technical details
The vulnerability is a path traversal flaw (CWE-22) in ATutor's ZIP extraction handling. An instructor-authenticated attacker can craft a malicious ZIP archive with directory traversal sequences (e.g., "../") in file paths that, when extracted, escape the intended extraction directory. By placing a .phtml (PHP-executable) file in the web root, the attacker achieves remote code execution with web server privileges. The vulnerability requires instructor-level authentication and knowledge of the target system. ATutor 2.2.4 is confirmed vulnerable; the product is no longer actively maintained and no patch has been released.
Affected products
- ATutor ATutor 2.2.4 confirmed vulnerable; other versions untested
Timeline
- 2026-08-20: disclosed
- 2026-08-20: advisory: CERT Polska advisory CVE-2026-64966