CVE-2025-66567
CriticalCVSS 9.1Exploitation Probability (EPSS)
Low risk32th percentile - higher than 32% of all known CVEs
Summary
The ruby-saml library up to version 1.12.4 contains an authentication bypass vulnerability due to an incomplete fix for CVE-2025-25292. Differences in XML parsing between ReXML and Nokogiri allow an attacker to perform a Signature Wrapping attack. The issue is fixed in version 1.18.0.
Risk Assessment
An attacker can bypass SAML authentication and gain unauthorized access to systems using ruby-saml, potentially leading to account takeover or privilege escalation.
Recommendation
Immediately upgrade ruby-saml to version 1.18.0 or later to remediate the vulnerability.
Other vulnerabilities in ruby-saml
See all- CVE-2016-5697High
Ruby-saml before version 1.3.0 allows attackers to perform XML signature wrapping attacks via unspecified vectors.
- CVE-2025-66568Critical
The ruby-saml library implements the client side of a SAML authorization. Versions up to and including 1.12.4 are vulnerable to authentication bypass through the libxml2 canonicalization process used by Nokogiri for document transformation, which allows an attacker to execute a Signature Wrapping attack. When libxml2's canonicalization is invoked on an invalid XML input, it may return an empty string rather than a canonicalized node. ruby-saml then proceeds to compute the DigestValue over this empty string, treating it as if canonicalization succeeded. This issue is fixed in version 1.18.0.
- CVE-2024-45409Critical
The Ruby SAML library (ruby-saml) in versions <= 12.2 and 1.13.0 through 1.16.0 does not properly verify the signature of the SAML Response. An unauthenticated attacker with access to any signed SAML document (from the IdP) can forge a SAML Response/Assertion with arbitrary contents and log in as any user.
Original NVD description (English source)
The ruby-saml library is for implementing the client side of a SAML authorization. ruby-saml versions up to and including 1.12.4 contain an authentication bypass vulnerability due to an incomplete fix for CVE-2025-25292. ReXML and Nokogiri parse XML differently, generating entirely different document structures from the same input. This allows an attacker to execute a Signature Wrapping attack. This issue is fixed in version 1.18.0.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS