ruby-saml Auth Bypass via ReXML/Nokogiri Diff <1.12.4/1.18.0
CVE-2025-25291 Published on March 12, 2025

ruby-saml vulnerable to SAML authentication bypass due to DOCTYPE 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 fix the issue.

Github Repository NVD

Weakness Types

Improper Verification of Cryptographic Signature

The software does not verify, or incorrectly verifies, the cryptographic signature for data.

Interpretation Conflict

Product A handles inputs or steps differently than Product B, which causes A to perform incorrect actions based on its perception of B's state. This is generally found in proxies, firewalls, anti-virus software, and other intermediary devices that monitor, allow, deny, or modify traffic based on how the client or server is expected to behave.


Products Associated with CVE-2025-25291

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Affected Versions

SAML-Toolkits ruby-saml:

Vulnerable Packages

The following package name and versions may be associated with CVE-2025-25291

Package Manager Vulnerable Package Versions Fixed In
rubygems omniauth-saml >= 2.2.0, < 2.2.3 2.2.3
rubygems omniauth-saml >= 2.0.0, < 2.1.3 2.1.3
rubygems omniauth-saml < 1.10.6 1.10.6

Exploit Probability

EPSS
13.85%
Percentile
94.20%

EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.