CVE-2025-25293
Prior to versions 1.12.4 and 1.18.0, 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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (1.50%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
ruby-saml provides security assertion markup language (SAML) single sign-on (SSO) for Ruby. Prior to versions 1.12.4 and 1.18.0, 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. This issue may lead to remote Denial of Service (DoS). Versions 1.12.4 and 1.18.0 fix the issue.
- CVSS 4.0
- 7.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 1.50% probability · 73th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-400
- Affected
- omniauth/omniauth saml · onelogin/ruby-saml
- Source
- security-advisories@github.com
References
- https://about.gitlab.com/releases/2025/03/12/patch-release-gitlab-17-9-2-releasedPatch
- https://github.blog/security/sign-in-as-anyone-bypassing-saml-sso-authentication-with-parser-differentialsExploit, Third Party Advisory
- https://github.com/SAML-Toolkits/ruby-saml/commit/acac9e9cc0b9a507882c614f25d41f8b47be349aPatch
- https://github.com/SAML-Toolkits/ruby-saml/commit/e2da4c6dae7dc01a4d9cd221395140a67e2b3eb1Patch
- https://github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.12.4Release Notes
- https://github.com/SAML-Toolkits/ruby-saml/releases/tag/v1.18.0Release Notes
- https://github.com/SAML-Toolkits/ruby-saml/security/advisories/GHSA-92rq-c8cf-prrqVendor Advisory
- https://github.com/omniauth/omniauth-saml/security/advisories/GHSA-hw46-3hmr-x9xvVendor Advisory
- https://securitylab.github.com/advisories/GHSL-2024-355_ruby-samlExploit, Third Party Advisory
- https://lists.debian.org/debian-lts-announce/2025/04/msg00011.html
- https://security.netapp.com/advisory/ntap-20250314-0008/Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.