Jenkins SAML Single Sign On(SSO) Plugin 2.0.2 and earlier does not perform permission checks in multiple HTTP endpoints.
This allows attackers with Overall/Read permission to send an HTTP request to an attacker-specified URL and parse the response as XML, or parse a local file on the Jenkins controller as XML.
As the plugin does not configure its XML parser to prevent XML external entity (XXE) attacks, attackers can have Jenkins parse a crafted XML response that uses external entities for extraction of secrets from the Jenkins controller or server-side request forgery.
Additionally, these HTTP endpoints do not require POST requests, resulting in a cross-site request forgery (CSRF) vulnerability.
SAML Single Sign On(SSO) Plugin 2.1.0 requires POST requests and Overall/Administer permission for the affected HTTP endpoints.