XWiki Platform Old Core: Resource path traversal via /skin/ action endpoint in Jetty 12+
With Jetty 12+ a user can craft a URL to access any resource the Jetty instance is allowed to access. For example http://[host]/xwiki/bin/skin/..%252f/..%252f..%252f..%252f..%252f..%252f..%252f..%252fetc/passwd allows downloading the content of the /etc/passwd file, provided Jetty is allowed to read it, and if your XWiki webapp is located exactly 5 levels below / (like /var/lib/jetty/webapps/xwiki, which is the case in the docker image, for example). Another example which does not go out of …