This advisory announces vulnerabilities in the following Jenkins deliverables:
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.
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.
Jenkins LTS 2.235.5 updates the bundled Jetty to 9.4.30.
Jetty was already previously updated to 9.4.30 in the 2.243 weekly release.
These versions include fixes to the vulnerabilities described above. All prior versions are considered to be affected by these vulnerabilities unless otherwise indicated.