Vulnerability Description
The SimpleSAMLphp SAML2 library is a PHP library for SAML2 related functionality. Prior to versions 4.17.0 and 5.0.0-alpha.20, there is a signature confusion attack in the HTTPRedirect binding. An attacker with any signed SAMLResponse via the HTTP-Redirect binding can cause the application to accept an unsigned message. Versions 4.17.0 and 5.0.0-alpha.20 contain a fix for the issue.
CVSS Score
HIGH
Related Weaknesses (CWE)
References
- https://github.com/simplesamlphp/saml2/blob/9545abd0d9d48388f2fa00469c5c1e0294f0
- https://github.com/simplesamlphp/saml2/blob/9545abd0d9d48388f2fa00469c5c1e0294f0
- https://github.com/simplesamlphp/saml2/commit/7867d6099dc7f31bed1ea10e5bea159c56
- https://github.com/simplesamlphp/saml2/security/advisories/GHSA-46r4-f8gj-xg56
- https://lists.debian.org/debian-lts-announce/2025/05/msg00013.html
FAQ
What is CVE-2025-27773?
CVE-2025-27773 is a vulnerability with a CVSS score of 8.6 (HIGH). The SimpleSAMLphp SAML2 library is a PHP library for SAML2 related functionality. Prior to versions 4.17.0 and 5.0.0-alpha.20, there is a signature confusion attack in the HTTPRedirect binding. An att...
How severe is CVE-2025-27773?
CVE-2025-27773 has been rated HIGH with a CVSS base score of 8.6/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2025-27773?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.