Impact
The cache action in action/cache.py allows directory traversal through a crafted HTTP request. An attacker who can upload attachments to
the wiki can use this to achieve remote code execution.
Patches
Users are strongly advised to upgrade to a patched version.
MoinMoin Wiki 1.9.11 has the necessary fixes and also contains other important fixes.
Workarounds
It is not advised to work around this, but to upgrade MoinMoin to a patched version.
That said, a work around via disabling the cache or the AttachFile action might be possible.
Also, it is of course helpful if you give write permissions (which include uploading attachments) only to trusted users.
Credits
This vulnerability was discovered by Michael Chapman.
For more information
If you have any questions or comments about this advisory, email me at twaldmann@thinkmo.de.
References
- https://github.com/moinwiki/moin-1.9/security/advisories/GHSA-52q8-877j-gghq
- https://github.com/moinwiki/moin-1.9/commit/6b96a9060069302996b5af47fd4a388fc80172b7
- https://pypi.org/project/moin/
- https://nvd.nist.gov/vuln/detail/CVE-2020-25074
- https://lists.debian.org/debian-lts-announce/2020/11/msg00020.html
- https://www.debian.org/security/2020/dsa-4787
- http://moinmo.in/SecurityFixes
- https://github.com/advisories/GHSA-52q8-877j-gghq