Vulnerability · Published Mar 12, 2025 · Assigned by GitHub_M
CVE-2025-25291ruby-saml vulnerable to SAML authentication bypass due to DOCTYPE handling (parser differential)
Critical 9.3
In plain English
A critical-severity security flaw in ruby-saml from SAML-Toolkits. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 21.0% (higher than 98% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
ruby-saml provides security assertion markup language (SAML) single sign-on (SSO) for Ruby. An authentication bypass vulnerability was found in ruby-saml prior to versions 1.12.4 and 1.18.0 due to a parser differential. ReXML and Nokogiri parse XML differently; the parsers can generate entirely different document structures from the same XML input. That allows an attacker to be able to execute a Signature Wrapping attack. This issue may lead to authentication bypass. Versions 1.12.4 and 1.18.0 fix the issue.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | ruby-saml | no fix listed | DEBIAN-CVE-2025-25291 |
| RubyGems | ruby-saml | 1.12.4 | GHSA-4vc4-m8qh-g8jm |
| RubyGems | ruby-saml | 1.18.0 | GHSA-4vc4-m8qh-g8jm |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| SAML-Toolkits | ruby-saml | < 1.12.4>= 1.13.0, < 1.18.0 |
Weakness: CWE-347, CWE-436 · Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
References
- https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-4vc4-m8qh-g8jm x_refsource_CONFIRM
- https://github.com/omniauth/omniauth-saml/security/advisories/GHSA-hw46-3hmr-x9xv x_refsource_MISC
- https://github.com/SAML-Toolkits/ruby-saml/commit/e76c5b36bac40aedbf1ba7ffaaf495be63328cd9 x_refsource_MISC
- https://github.com/SAML-Toolkits/ruby-saml/commit/e9c1cdbd0f9afa467b585de279db0cbd0fb8ae97 x_refsource_MISC
- https://about.gitlab.com/releases/2025/03/12/patch-release-gitlab-17-9-2-released x_refsource_MISC
- https://github.blog/security/sign-in-as-anyone-bypassing-saml-sso-authentication-with-parser-differentials x_refsource_MISC
- https://github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.12.4 x_refsource_MISC
- https://github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.18.0 x_refsource_MISC
- https://portswigger.net/research/saml-roulette-the-hacker-always-wins x_refsource_MISC
- https://securitylab.github.com/advisories/GHSL-2024-329_GHSL-2024-330_ruby-saml x_refsource_MISC
- https://security.netapp.com/advisory/ntap-20250314-0010/
- https://news.ycombinator.com/item?id=43374519
- https://lists.debian.org/debian-lts-announce/2025/04/msg00011.html