Wagtail is an open source content management system built on Django. Prior to 7.0.9, 7.3.4, 7.4.3, and 8.0rc2, Wagtail applies ETag conditional request processing to the document serve endpoint before document permission and filename checks complete. An unauthenticated attacker who knows a document ID and a candidate SHA1 hash can submit If-Match or If-None-Match and distinguish the response, revealing whether that hash is present in the document library. The issue does not expose document contents, filenames, other metadata, or information about hashes the attacker does not already know. This issue is fixed in versions 7.0.9, 7.3.4, 7.4.3, and 8.0rc2.

Affected: PyPI: wagtail

### Impact By passing specific HTTP headers to the document serve URL endpoint, an attacker was able to determine whether a document with a given ID matched a specified SHA1 hash, regardless of any permission restrictions on the document or knowing its filename. This could allow an attacker to determine whether a document with a specific known hash is present in the Wagtail document library.

This vulnerability does not expose the document's contents or any metadata beyond the already known SHA1 hash, and does not expose information about any documents for which the attacker does not know the SHA1 hash.

### Patches Patched versions have been released as Wagtail 7.0.9, 7.3.4, 7.4.3 and 8.0rc2.

### Workarounds Site owners who are unable to upgrade can strip `If-Match` and `If-None-Match` from anonymous requests to `/documents/` at the reverse proxy, or use a custom document model without a `file_hash` attribute.

### Acknowledgements Many thanks to Anand Himanshu for reporting this issue.

### For more information If you have any questions or comments about this advisory:

* Visit Wagtail's [support channels](https://docs.wagtail.org/en/stable/support.html) * Email us at [security@wagtail.org](mailto:security@wagtail.org) (view our [security policy](https://github.com/wagtail/wagtail/security/policy) for more information).