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Fencer Vulns
high 7.5

CVE-2021-22904 json

Possible DoS Vulnerability in Action Controller Token Authentication

published 2021-05-05 5 y ago modified 2026-06-17 4 mo ago also GHSA-7wjx-3g7j-8584 , EUVD-2021-1009

cvss
7.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
4.9%
EPSS 4.9% chance of exploitation in 30 days, percentile 92%
public exploits
0
none known

Summary

The actionpack ruby gem before 6.1.3.2, 6.0.3.7, 5.2.4.6, 5.2.6 suffers from a possible denial of service vulnerability in the Token Authentication logic in Action Controller due to a too permissive regular expression. Impacted code uses `authenticate_or_request_with_http_token` or `authenticate_with_http_token` for request authentication.

Patch / fix

  • rubygems actionpack 5.2.4.6, 5.2.6, 6.0.3.7, 6.1.3.2
  • rubyonrails rails 5.2.4.6, 5.2.6, 6.0.3.7, 6.1.3.2
  • rails Debian 14, Debian 13, Debian 12 2:6.0.3.7+dfsg-1

debian advisories DEBIAN-CVE-2021-22904

  • foreman satellite capsule 6.10, satellite 6.10 2.5.2.17-2.el7sat
  • candlepin satellite 6.10 4.0.9-1.el7sat
  • satellite satellite capsule 6.10, satellite 6.10 6.10.0-3.el7sat
  • python-ecdsa satellite capsule 6.10, satellite 6.10 0.13.3-2.el7pc
  • python-pyyaml satellite capsule 6.10, satellite 6.10 5.4.1-1.el7pc
  • python3-ecdsa satellite capsule 6.10, satellite 6.10 0.13.3-2.el7pc
  • python-aiohttp satellite capsule 6.10, satellite 6.10 3.7.4-1.el7pc
  • python-urllib3 satellite capsule 6.10, satellite 6.10 1.26.5-1.el7pc

red hat advisories RHSA-2021:4702

  • rubygem-activesupport-5_1 SLE High Availability Extension 15 SP4, SLE High Availability Extension 15 SP3, SLE High Availability Extension 15 SP2 +4 more 5.1.4-150000.3.6.1
  • rubygem-actionpack-5_1 SLE High Availability Extension 15 SP4, SLE High Availability Extension 15 SP3, SLE High Availability Extension 15 SP2 +4 more 5.1.4-150000.3.12.1

suse advisories SUSE-SU-2022:2108-1

  • rubygem-actionpack-6.0 openSUSE Tumbleweed 6.0.4.4-1.1

opensuse advisories openSUSE-SU-2024:11821-1

  • redmine Arch Linux 4.2.2-1
  • metasploit Arch Linux 6.0.48-1
  • gitlab Arch Linux 14.0.0-1
  • gitlab-gitaly Arch Linux 14.1.0-1

arch linux advisories AVG-1920AVG-1921AVG-2090AVG-2223

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-22904 updated cvss 7.5

rails: Possible DoS Vulnerability in Action Controller Token Authentication

  • Red Hat CloudForms Management Engine 5 cfme-gemset
    affected: no fix planned “Will not fix”
  • Red Hat 3scale API Management Platform 2 system
    affected: no fix available
  • Red Hat Satellite 6 tfm-ror52-rubygem-actionpack
    affected: no fix planned “Will not fix”
  • Red Hat Satellite 6.10 tfm-rubygem-rails 6.0.3.7-1.el7sat
    fixed: vendor fix RHSA-2021:4702
  • Red Hat Satellite 6.10 tfm 7.0-1.el7sat, gofer 2.12.5-7.el7sat, katello 4.1.1-2.el7sat, libsolv 0.7.20-1.el7pc, receptor 0.6.4-2.el7ar, libcomps 0.1.15-1.el7pc, +581 more Red Hat Satellite Capsule 6.10 tfm 7.0-1.el7sat, katello 4.1.1-2.el7sat, libsolv 0.7.20-1.el7pc, libcomps 0.1.15-1.el7pc, python-rq 1.8.1-1.el7pc, python-idna 2.10-1.el7pc, +355 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

4.87% chance of exploitation in the next 30 days, higher than 92% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • discuss.rubyonrails.org https://discuss.rubyonrails.org/t/cve-2021-22904-possible-dos-vulnerability-in-action-controller-token-authentication/77869 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
rubygems actionpack
>=6.0.0, <6.0.3.7
>=6.1.0, <6.1.3.2
>=5.2.5, <5.2.6
>=4.0.0, <5.2.4.6
6.0.3.7
6.1.3.2
5.2.6
5.2.4.6

Affected products

  • n/a https://github.com/rails/rails

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.