What’s Vulnerable › Vulnerabilities
CVE-2021-45115: Denial-of-service in Django
- Severity: high (CVSS 7.5 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 2.4% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2022-01-05 · updated 2026-06-17
Description
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.
Affected products
- Django: from 2.2 before 2.2.26; from 3.2 before 3.2.11; from 4.0 before 4.0.1 — fixed in 2.2.26, 3.2.11, 4.0.1
- Fedoraproject Fedora: 35
- Pypi Django: from 2.2 before 2.2.26; from 3.2 before 3.2.11; from 4.0 before 4.0.1; 2.2, 2.2.1, 2.2.10, 2.2.11, 2.2.12, 2.2.13 (+32) — fixed in 2.2.26, 3.2.11, 4.0.1
How to fix
Upgrade to a fixed version: Django 2.2.26, 3.2.11, 4.0.1; Pypi Django 2.2.26, 3.2.11, 4.0.1. Check the vendor advisory for mitigations.
References
- https://docs.djangoproject.com/en/4.0/releases/security/
- https://groups.google.com/forum/#%21forum/django-announce
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/B4SQG2EAF4WCI2SLRL6XRDJ3RPK3ZRDV/
- https://security.netapp.com/advisory/ntap-20220121-0005/
- https://www.djangoproject.com/weblog/2022/jan/04/security-releases/
- https://docs.djangoproject.com/en/4.0/releases/security/
- https://groups.google.com/forum/#%21forum/django-announce
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/B4SQG2EAF4WCI2SLRL6XRDJ3RPK3ZRDV/
- https://security.netapp.com/advisory/ntap-20220121-0005/
- https://www.djangoproject.com/weblog/2022/jan/04/security-releases/
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