Description: An attacker that is able to modify Velocity templates may execute arbitrary Java code or run arbitrary system commands with the same privileges as the account running the Servlet container. This applies to applications that allow untrusted users to upload/modify velocity templates running Apache Velocity Engine versions up to 2.2.
Mitigation: Applications using Apache Velocity that allow untrusted users to upload templates should upgrade to version 2.3. This version adds additional default restrictions on what methods/properties can be accessed in a template. Credit: This issue was discovered by Alvaro Munoz pwntes...@github.com of Github Security Labs and was originally reported as GHSL-2020-048.
