Ce mail provient de l'extérieur, restons vigilants ===================================================================== CERT-Renater Note d'Information No. 2025/VULN850 _____________________________________________________________________ DATE : 12/12/2025 HARDWARE PLATFORM(S): / OPERATING SYSTEM(S): Systems running ruby-saml (RubyGems) versions prior to 1.18.0. ===================================================================== https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-x4h9-gwv3-r4m4 https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-9v8j-x534-2fx3 _____________________________________________________________________ Libxml2 Canonicalization error can bypass Digest/Signature validation Critical pitbulk published GHSA-x4h9-gwv3-r4m4 Dec 8, 2025 Package ruby-saml (RubyGems) Affected versions < 1.18.0 Patched versions >= 1.18.0 Description Summary Ruby-saml up to and including 1.12.4, there is an authentication bypass vulnerability because of an issue at libxml2 canonicalization process used by Nokogiri for document transformation. That allows an attacker to be able to execute a Signature Wrapping attack. The vulnerability does not affect the version 1.18.0. Details 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. Impact Digest bypass: By crafting input that causes canonicalization to yield an empty string, the attacker can manipulate validation to pass incorrectly. Signature replay on empty canonical form: If an empty string has been signed once (e.g., in a prior interaction or via a misconfigured flow), that signature can potentially be replayed to bypass authentication. Severity Critical 9.3/ 10 CVSS v4 base metrics Exploitability Metrics Attack Vector Network Attack Complexity Low Attack Requirements None Privileges Required None User interaction None Vulnerable System Impact Metrics Confidentiality High Integrity High Availability None Subsequent System Impact Metrics Confidentiality None Integrity None Availability None 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 CVE ID CVE-2025-66568 Weaknesses Weakness CWE-347 Credits @d0ge d0ge Reporter _____________________________________________________________________ SAML authentication bypass due to namespace handling (parser differential) Critical pitbulk published GHSA-9v8j-x534-2fx3 Dec 8, 2025 Package ruby-saml (RubyGems) Affected versions < 1.18.0 Patched versions >= 1.18.0 Description Summary Ruby-saml up to and including 1.12.4, there is an authentication bypass vulnerability because of an incomplete fix for CVE-2025-25292. 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. The vulnerability does not affect the version 1.18.0. Impact That allows an attacker to be able to execute a Signature Wrapping attack and bypass the authentication Severity Critical 9.3/ 10 CVSS v4 base metrics Exploitability Metrics Attack Vector Network Attack Complexity Low Attack Requirements None Privileges Required None User interaction None Vulnerable System Impact Metrics Confidentiality High Integrity High Availability None Subsequent System Impact Metrics Confidentiality None Integrity None Availability None 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 CVE ID CVE-2025-66567 Weaknesses Weakness CWE-347 Credits @d0ge d0ge Reporter ========================================================= + CERT-RENATER | tel : 01-53-94-20-44 + + 23/25 Rue Daviel | fax : 01-53-94-20-41 + + 75013 Paris | email:cert@support.renater.fr + =========================================================