Headline
CVE-2022-41956: File disclosure via remote handin feature
Autolab is a course management service, initially developed by a team of students at Carnegie Mellon University, that enables instructors to offer autograded programming assignments to their students over the Web. A file disclosure vulnerability was discovered in Autolab’s remote handin feature, whereby users are able to hand-in assignments using paths outside their submission directory. Users can then view the submission to view the file’s contents. The vulnerability has been patched in version 2.10.0. As a workaround, ensure that the field for the remote handin feature is empty (Edit Assessment > Advanced > Remote handin path), and that you are not running Autolab as root
(or any user that has write access to /
). Alternatively, disable the remote handin feature if it is unneeded by replacing the body of local_submit
in app/controllers/assessment/handin.rb
with render(plain: "Feature disabled", status: :bad_request) && return
.
Impact
A file disclosure vulnerability was discovered in Autolab’s remote handin feature, whereby users are able to hand-in assignments using paths outside their submission directory. Users can then view the submission to view the file’s contents.
Patches
The vulnerability has been patched in v2.10.0.
Workarounds
Ensure that the field for the remote handin feature is empty (Edit Assessment > Advanced > Remote handin path), and that you are not running Autolab as root (or any user that has write access to /).
Alternatively, disable the remote handin feature if it is unneeded by replacing the body of local_submit in app/controllers/assessment/handin.rb with render(plain: "Feature disabled", status: :bad_request) && return.
References
- Rails Path Traversal
For more information
If you have any questions or comments about this advisory:
- Open an issue in https://github.com/autolab/Autolab/
- Email us at [email protected]