GHSA-qj4x-9g63-25g6 XWiki Platform Old Core: Resource path traversal via /skin/ action endpoint in Jetty 12+

• Maven org.xwiki.platform:xwiki-platform-oldcore: < 17.10.5 → fixed in 17.10.5 • Maven org.xwiki.platform:xwiki-platform-oldcore: >= 18.0.0-rc-1, < 18.2.0 → fixed in 18.2.0

Impact 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 the XWiki webapp, but it's still a vulnerability (since users should not be allowed to access Hibernate or XWiki configuration files) is `http://[host]/xwiki/bin/skin/..%252f/..%252fWEB-INF/xwiki.cfg`. Patches This vulnerability has been patched in XWiki 17.10.5 and 18.2.0. Workarounds A possible workaround is to use a different application server, like Jetty < 12 (in the case of XWiki < 17) or Tomcat, which don't seem to be impacted. Resources • https://jira.xwiki.org/browse/XWIKI-24075 • https://jira.xwiki.org/browse/XCOMMONS-3594 For more information If there are any questions or comments about this advisory: • Open an issue in Jira XWiki.org • Send an email to the Security Mailing List Attribution Lê Ngọc Khoa reported the vulnerability.