An issue was discovered in Django 2.2 before 2.2.26, 3.2 before 3.2.11, and 4.0 before 4.0.1. UserAttributeSimilarityValidator incurred significant overhead in evaluating a submitted password that was artificially large in relation to the comparison values. In a situation where access to user registration was unrestricted, this provided a potential vector for a denial-of-service attack.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-45115
• https://groups.google.com/forum/#!forum/django-announce
• django/django@2135637
• django/django@a8b32fe
• django/django@df79ef0
• https://docs.djangoproject.com/en/4.0/releases/security
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/B4SQG2EAF4WCI2SLRL6XRDJ3RPK3ZRDV
• https://security.netapp.com/advisory/ntap-20220121-0005
• https://www.djangoproject.com/weblog/2022/jan/04/security-releases