Incorrect Permission Assignment for Critical Resource in Jenkins Mailer Plugin

Jenkins Mailer Plugin prior to 408.vd726a_1130320 and 1.34.2 does not perform a permission check in a method implementing form validation.

This allows attackers with Overall/Read access to use the DNS used by the Jenkins instance to resolve an attacker-specified hostname.

Additionally, this form validation method does not require POST requests, resulting in a cross-site request forgery (CSRF) vulnerability.

Mailer Plugin 408.vd726a_1130320 and 1.34.2 requires POST requests and Overall/Administer permission for the affected form validation method.