CVE-2021-45115 Denial-of-service in Django

What is CVE-2021-45115?

CVE-2021-45115 is a high-severity denial of service vulnerability in Djangoproject Django, published on 4 Jan 2022. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official 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.

Which versions are affected by CVE-2021-45115?

8 open source packages ship an affected version, including django and Django. It affects 2 products.

Products include Djangoproject Django, Fedoraproject Fedora.

How do I fix CVE-2021-45115?

Upgrade django to a fixed version for your release line: 2.2.26, 3.2.11 or 4.0.1.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2021-45115 being exploited?

There is no known exploitation of CVE-2021-45115 in the wild and no public exploit code.

Other vulnerabilities in Djangoproject Django

• CVE-2026-4277 Privilege abuse in GenericInlineModelAdmin Critical 9.8
• CVE-2024-53908 Django SQL injection in HasKey(lhs, rhs) on Oracle Critical 9.8
• CVE-2024-42005 Django SQL injection vulnerability Critical 9.8
• CVE-2023-31047 Django bypasses validation when using one form field to upload multiple files Critical 9.8
• CVE-2022-34265 Django `Trunc()` and `Extract()` database functions vulnerable to SQL Injection Critical 9.8

All Djangoproject Django vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as BIT-django-2021-45115, DEBIAN-CVE-2021-45115, GHSA-53qw-q765-4fww, PYSEC-2022-1, UBUNTU-CVE-2021-45115.