Potential Observable Timing Discrepancy in Wagtail

Vulnerability Description

In Wagtail before versions 2.7.3 and 2.8.2, a potential timing attack exists on pages or documents that have been protected with a shared password through Wagtail's "Privacy" controls. This password check is performed through a character-by-character string comparison, and so an attacker who is able to measure the time taken by this check to a high degree of accuracy could potentially use timing differences to gain knowledge of the password. This is [understood to be feasible on a local network, but not on the public internet](https://groups.google.com/d/msg/django-developers/iAaq0pvHXuA/fpUuwjK3i2wJ). Privacy settings that restrict access to pages/documents on a per-user or per-group basis (as opposed to a shared password) are unaffected by this vulnerability. This has been patched in 2.7.3, 2.8.2, 2.9.

References

• https://github.com/wagtail/wagtail/security/advisories/GHSA-jjjr-3jcw-f8v6
• https://github.com/wagtail/wagtail/commit/3c030490ed575bb9cd01dfb3a890477dcaeb2edf
• https://github.com/wagtail/wagtail/commit/b76ab57ee859732b9cf9287d380493ab24061090
• https://github.com/wagtail/wagtail/commit/ba9d424bd1ca5ce1910d3de74f5cc07214fbfb11
• https://github.com/wagtail/wagtail/commit/bac3cd0a26b023e595cf2959aae7da15bb5e4340