Description
The CORS Filter in Apache Tomcat 9.0.0.M1 to 9.0.0.M21, 8.5.0 to 8.5.15, 8.0.0.RC1 to 8.0.44 and 7.0.41 to 7.0.78 did not add an HTTP Vary header indicating that the response varies depending on Origin. This permitted client and server side cache poisoning in some circumstances.
Mitigation
We recommend upgrading to a version of this component that is not vulnerable to this specific issue.