CVE-2025-25292

Ruby SAML vulnerable to SAML authentication bypass due to namespace handling (parser differential)

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 contain a patch for the issue.

Affected

SAML-Toolkits · ruby-saml

CVSS v4.0 GITHUB

9.3 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v4.0 GitHub

9.3 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

CVSS v3.1 NVD

9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

65.09% chance of exploitation in the next 30 days, 99th percentile

Published

2025-03-12

Updated

2025-11-03

Proof-of-concept exploits (1)

• https://github.blog/security/sign-in-as-anyone-bypassing-saml-sso-authentication-with-par…

Security advisories

• SAML-Toolkits/ruby-saml/security/advisories/GHSA-754f-8gm6-c4r2
• omniauth/omniauth-saml/security/advisories/GHSA-hw46-3hmr-x9xv
• https://portswigger.net/research/saml-roulette-the-hacker-always-wins
• https://security.netapp.com/advisory/ntap-20250314-0009
• https://securitylab.github.com/advisories/GHSL-2024-329_GHSL-2024-330_ruby-saml
• advisories/GHSA-754f-8gm6-c4r2
• https://about.gitlab.com/releases/2025/03/12/patch-release-gitlab-17-9-2-released
• SAML-Toolkits/ruby-saml/commit/e76c5b36bac40aedbf1ba7ffaaf495be63328cd9
• https://news.ycombinator.com/item?id=43374519

References

• CVE Record
• NVD entry