CVE-2025-25293: Ruby SAML allows remote Denial of Service (DoS) with compressed SAML responses
(updated )
ruby-saml is susceptible to remote Denial of Service (DoS) with compressed SAML responses.
Ruby-saml uses zlib to decompress SAML responses in case they’re compressed. It is possible to bypass the message size check with a compressed assertion since the message size is checked before inflation and not after.
References
- about.gitlab.com/releases/2025/03/12/patch-release-gitlab-17-9-2-released
- github.blog/security/sign-in-as-anyone-bypassing-saml-sso-authentication-with-parser-differentials
- github.com/SAML-Toolkits/ruby-saml
- github.com/SAML-Toolkits/ruby-saml/commit/acac9e9cc0b9a507882c614f25d41f8b47be349a
- github.com/SAML-Toolkits/ruby-saml/commit/e2da4c6dae7dc01a4d9cd221395140a67e2b3eb1
- github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.12.4
- github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.18.0
- github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-92rq-c8cf-prrq
- github.com/advisories/GHSA-92rq-c8cf-prrq
- github.com/omniauth/omniauth-saml/security/advisories/GHSA-hw46-3hmr-x9xv
- github.com/rubysec/ruby-advisory-db/blob/master/gems/ruby-saml/CVE-2025-25293.yml
- lists.debian.org/debian-lts-announce/2025/04/msg00011.html
- nvd.nist.gov/vuln/detail/CVE-2025-25293
- security.netapp.com/advisory/ntap-20250314-0008
- securitylab.github.com/advisories/GHSL-2024-355_ruby-saml
Code Behaviors & Features
Detect and mitigate CVE-2025-25293 with GitLab Dependency Scanning
Secure your software supply chain by verifying that all open source dependencies used in your projects contain no disclosed vulnerabilities. Dependency Scanning using SBOM also detects vulnerabilities from proprietary advisories that this site does not include. Learn more about Dependency Scanning using SBOM →