Autolab is a course management service that enables auto-graded programming assignments. A Tar slip vulnerability was found in the Install assessment functionality of Autolab. To exploit this vulnerability an authenticated attacker with instructor permissions needs to upload a specially crafted Tar file. Using the install assessment functionality an attacker can feed a Tar file that contain files with paths pointing outside of the target directory (e.g., `../../../../tmp/tarslipped1.sh`). When the Install assessment form is submitted the files inside of the archives are expanded to the attacker-chosen locations. This issue has been addressed in version 2.11.0. Users are advised to upgrade.
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.