Jenkins Nerrvana Plugin 1.02.06 and earlier does not configure its XML parser to prevent XML external entity (XXE) attacks.

This allows attackers with Overall/Read permission to have Jenkins parse a crafted HTTP request with XML data that uses external entities for extraction of secrets from the Jenkins controller or server-side request forgery.

Additionally, XML parsing is exposed as a form validation endpoint that does not require POST requests, allowing exploitation by users without Overall/Read permission via CSRF.

References

• https://nvd.nist.gov/vuln/detail/CVE-2020-2298
• https://www.jenkins.io/security/advisory/2020-10-08/#SECURITY-2097
• http://www.openwall.com/lists/oss-security/2020/10/08/5