In the Tarfile.extract() function, the filter parameter is not passed properly when extracting hardlinks. An affected system that extracts content from untrusted tar files could end up writing files with an unexpected uid/gid despite the user passing filter=data to the extract() function.
Weakness
The product does not preserve permissions or incorrectly preserves permissions when copying, restoring, or sharing objects, which can cause them to have less restrictive permissions than intended.
References
- https://github.com/python/cpython/commit/5e0ef3f1afe892e4f64eb83368db57ac4c40cba0
- https://github.com/python/cpython/commit/7b57e8d51446297b8c7c482d224bc5f1938e4301
- https://github.com/python/cpython/commit/7ccdbaba2c54250a70d7f25632152df7655a5e0a
- https://github.com/python/cpython/commit/eee3ddf0ca10283cc7fea724aae9cd8665f8d15e
- https://github.com/python/cpython/issues/151987
- https://github.com/python/cpython/pull/151988
- https://mail.python.org/archives/list/security-announce@python.org/thread/TWZW2PC2AZOV6FENIHFSRC63OM7MBGSB/