SimpleSAMLphp has Possible DoS via XPath Transform
Impact
This library turned out to be vulnerable to Denial-of-Service attacks using XPath transforms. A mitigation has been put in place to restrict the number of transforms and to restrict transforms to only the transform-algorithms mentioned in the SAML 2.0 Core Specifications (and specifically refuse XPath transforms).
Source excerpt · OSVAffected packages
Start with the recorded fix for your release branch. Check your installed version and test compatibility before upgrading. Fixing this advisory does not rule out other vulnerabilities in the release.
| Affected range | Recorded fix |
|---|---|
| From 4.20.0 before 4.20.3Ecosystem versions | 4.20.3 |
| Earlier releases before 4.19.3Ecosystem versions | 4.19.3 |
Version evidence: OSV · GHSA-5cjr-mxj5-wmrx
View original version evidence (155 explicit versions)
| Affected range | Recorded fix |
|---|---|
| From 4.20.0 before 4.20.3Ecosystem versions | 4.20.3 |
| Earlier releases before 4.19.3Ecosystem versions | 4.19.3 |
Version evidence: OSV · GHSA-5cjr-mxj5-wmrx
View original version evidence (153 explicit versions)
Original source description
Summary
This library turned out to be vulnerable to Denial-of-Service attacks using XPath transforms. A mitigation has been put in place to restrict the number of transforms and to restrict transforms to only the transform-algorithms mentioned in the SAML 2.0 Core Specifications (and specifically refuse XPath transforms).
Impact
An attacker is able to send specially crafted messages to any entity relying on SimpleSAMLphp (or directly on this SAML2-library) to be able to perform a Denial-of-Service attack.