Medium · published May 26, 2023
Autolab is a course management service that enables auto-graded programming assignments. A Tar slip vulnerability was found in the MOSS cheat checker functionality of Autolab. To exploit this vulnerability an authenticated attacker with instructor permissions needs to upload a specially crafted Tar file. Both "Base File Tar" and "Additional file archive" can be fed with Tar files that contain paths outside their target directories (e.g., `../../../../tmp/tarslipped2.sh`). When the MOSS cheat checker is started the files inside of the archives are expanded to the attacker-chosen locations. This issue may lead to arbitrary file write within the scope of the running process. This issue has been addressed in version 2.11.0. Users are advised to upgrade.