CVE-2021-22902: rubyonrails rails Uncontrolled Resource Consumption
Vulnerability summary
CVE-2021-22902 is a high (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in rubyonrails rails. EPSS estimates a 2.87% chance of exploitation in the next 30 days, higher than 86.5% of scored vulnerabilities. 1 public exploit is recorded.
Advisory lineage
Upstream 0 · Downstream 2 · Related 1Timeline
- 11-06-2021PublishedVulnerability first disclosed.
- 03-08-2024Last modifiedVulnerability information updated.
Description
The actionpack ruby gem (a framework for handling and responding to web requests in Rails) before 6.0.3.7, 6.1.3.2 suffers from a possible denial of service vulnerability in the Mime type parser of Action Dispatch. Carefully crafted Accept headers can cause the mime type parser in Action Dispatch to do catastrophic backtracking in the regular expression engine.
CVSS metrics
5 scores · 4 sources · 2 versions- OSV · UbuntuEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · DebianEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- OSV · RubygemsEcosystem advisory · calculated7.5HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS trend
Probability
2.87%
Chance of exploitation in the next 30 days
Percentile
87%
Versus all other CVEs
30-day change
+0.08 pp
From 2.79% on 19-09-2026
Known exploited
Compare KEV catalogsNot in any of the 3 tracked catalogs.
Public exploits
1 foundExploit Reference (discuss.rubyonrails.org)
Maturity: unknown
Weaknesses
CWE · root causeAffected systems
Debian1 product
- rails< 2:6.0.3.7+dfsg-1
RubyGems1 product
- actionpack≥ 6.0.0, < 6.0.3.7 | ≥ 6.1.0, < 6.1.3.2
Rubyonrails1 product
- rails≥ 6.0.0, < 6.0.3.7 | ≥ 6.1.0, < 6.1.0.2
Ubuntu1 product
- railsAll versions (No fix recorded)
4 vendors · 4 products
