Critical flaw in Jenkins Server could lead to information divulgence

A serious flaw in Jenkins server software, tracked as  CVE-2019-17638, could cause memory corruption and revelation of confidential data.

Jenkins, the most popular open source automation server, is maintained by CloudBees and the Jenkins community. It helps developers build, test and deploy their applications, and has millions of active installations globally with over 1 million users.

“Jenkins bundles Winstone-Jetty, a wrapper around Jetty, to act as HTTP and servlet server when started using java -jar jenkins.war. This is how Jenkins is run when using any of the installers or packages, but not when run using servlet containers such as Tomcat,” the advisory published by the company reads.

“Jenkins 2.224 through 2.242 and LTS 2.222.1 through 2.235.4 bundles Jetty 9.4.27 with the security vulnerability CVE-2019-17638. This vulnerability may allow unauthenticated attackers to obtain HTTP response headers that may include sensitive data intended for another user.”

“The issue was in the case of a buffer overflow, we released the header buffer, but did not null the field,” Jetty’s project head Greg Wilkins said.

Jenkins users are advised to update their software to the latest version to alleviate the buffer corruption fault.