CVE-2021-22880: Active Record subject to Regular Expression Denial-of-Service (ReDoS)

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 4.4% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2021-02-11 · updated 2026-06-17
Weakness: CWE-400

Description

The PostgreSQL adapter in Active Record before 6.1.2.1, 6.0.3.5, 5.2.4.5 suffers from a regular expression denial of service (REDoS) vulnerability. Carefully crafted input can cause the input validation in the `money` type of the PostgreSQL adapter in Active Record to spend too much time in a regular expression, resulting in the potential for a DoS attack. This only impacts Rails applications that are using PostgreSQL along with money type columns that take user input.

Affected products

Fedoraproject Fedora: 32, 33
Ruby on Rails: from 4.2.0 before 5.2.4.5; from 6.0.0 before 6.0.3.5; from 6.1.0 before 6.1.2.1 — fixed in 5.2.4.5, 6.0.3.5, 6.1.2.1
Rubygems Activerecord: from 5.0.0 before 5.2.4.5; from 6.0.0 before 6.0.3.5; from 6.1.0 before 6.1.2.1; 5.0.0, 5.0.0.1, 5.0.1, 5.0.1.rc1, 5.0.1.rc2, 5.0.2 (+68) — fixed in 5.2.4.5, 6.0.3.5, 6.1.2.1

How to fix

Upgrade to a fixed version: Ruby on Rails 5.2.4.5, 6.0.3.5, 6.1.2.1; Rubygems Activerecord 5.2.4.5, 6.0.3.5, 6.1.2.1. Check the vendor advisory for mitigations.

References

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