Description
XWiki Platform Attachment UI provides a macro to easily upload and select attachments for XWiki Platform, a generic wiki platform. Starting with version 14.0-rc-1 and prior to 14.4-rc-1, it's possible to store JavaScript in an attachment name, which will be executed by anyone trying to move the corresponding attachment. This issue has been patched in XWiki 14.4-rc-1. As a workaround, one may copy `moveStep1.vm` to `webapp/xwiki/templates/moveStep1.vm` and replace vulnerable code with code from the patch.
Remediation
References
https://raw.githubusercontent.com/xwiki/xwiki-platform/xwiki-platform-14.0-rc-1/xwiki-platform-core/xwiki-platform-attachment/xwiki-platform-attachment-api/src/main/resources/templates/attachment/moveStep1.vm
https://github.com/xwiki/xwiki-platform/security/advisories/GHSA-9r9j-57rf-f6vj
https://jira.xwiki.org/browse/XWIKI-19667
https://github.com/xwiki/xwiki-platform/commit/fbc4bfbae4f6ce8109addb281de86a03acdb9277