Summaryinfo

A vulnerability labeled as critical has been found in SAML-Toolkits ruby-saml up to 1.17.x. This issue affects some unknown processing of the component libxml2 Canonicalization. The manipulation results in signature verification. This vulnerability is reported as CVE-2025-66568. The attack can be launched remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in SAML-Toolkits ruby-saml up to 1.17.x. It has been classified as critical. Affected is an unknown part of the component libxml2 Canonicalization. The manipulation with an unknown input leads to a signature verification vulnerability. CWE is classifying the issue as CWE-347. The product does not verify, or incorrectly verifies, the cryptographic signature for data. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

The ruby-saml library implements the client side of an 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.

The advisory is shared for download at github.com. This vulnerability is traded as CVE-2025-66568 since 12/04/2025. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are neither technical details nor an exploit publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 278384 (Linux Distros Unpatched Vulnerability : CVE-2025-66568), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 1.18.0 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (278384). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Type

• Programming Language Software

Vendor

• SAML-Toolkits

Name

• ruby-saml

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.11
• 1.12
• 1.13
• 1.14
• 1.15
• 1.16
• 1.17

Website

• Product: https://github.com/SAML-Toolkits/ruby-saml/

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