Description
XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. Any user who can create a space can become admin of that space through App Within Minutes. The admin right implies the script right and thus allows JavaScript injection. The vulnerability can be exploited by creating an app in App Within Minutes. If the button should be disabled because the user doesn't have global edit right, the app can also be created by directly opening `/xwiki/bin/view/AppWithinMinutes/CreateApplication?wizard=true` on the XWiki installation. This has been patched in XWiki 13.10.11, 14.4.8, 14.10.1 and 15.0 RC1 by not granting the space admin right if the user doesn't have script right on the space where the app is created. Error message are displayed to warn the user that the app will be broken in this case. Users who became space admin through this vulnerability won't loose the space admin right due to the fix, so it is advised to check if all users who created AWM apps should keep their space admin rights. Users are advised to upgrade. There are no known workarounds for this vulnerability.
Remediation
References
https://github.com/xwiki/xwiki-platform/commit/e73b890623efa604adc484ad82f37e31596fe1a6
https://github.com/xwiki/xwiki-platform/security/advisories/GHSA-44h9-xxvx-pg6x
https://jira.xwiki.org/browse/XWIKI-20190