[org.jenkins-ci.plugins:fstrigger] XXE vulnerability in Jenkins Filesystem Trigger Plugin

Filesystem Trigger Plugin 0.40 and earlier does not configure its XML parser to prevent XML external entity (XXE) attacks.

This allows attackers with Job/Configure permission or otherwise able to control the contents of an XML file being polled for changes to have Jenkins parse a crafted XML document that uses external entities for extraction of secrets from the polling Jenkins controller or agent, server-side request forgery, or denial-of-service attacks.

Filesystem Trigger Plugin 0.41 disables external entity resolution for its XML parser.

References

• https://nvd.nist.gov/vuln/detail/CVE-2021-21657
• https://www.jenkins.io/security/advisory/2021-05-25/#SECURITY-2339
• http://www.openwall.com/lists/oss-security/2021/05/25/3
• https://github.com/advisories/GHSA-cphv-7cxw-5hcc