XWiki vulnerable to click-jacking through CSS injection in comments

Impact

It's possible using comments to inject CSS that would transform the full wiki in a link area leading to a malicious page. All versions of XWiki are impacted by this kind of attack.

Patches

The problem has been patched not by preventing injecting CSS in comments, which is currently a feature of XWiki, but by requiring confirmation from users when driving them to untrusted domains after clicking on a link, thus preventing any click-jacking attack.
This security measure has been put in place in XWiki 17.9.0, 17.4.6, 16.10.13.

Workarounds

There's no out-of-the-box workaround, but it should be possible to partly reuse the javascript code provided for the security measure in a JSX object inside the wiki, to request the same kind of confirmation.

References

• JIRA ticket: https://jira.xwiki.org/browse/XWIKI-23433
• Documentation of the new security measure: https://www.xwiki.org/xwiki/bin/view/ReleaseNotes/Data/XWiki/17.9.0RC1/Entry006/
• Commit for the security fix: https://github.com/xwiki/xwiki-platform/commit/29cb81f3a5387cf822d7e7534bdd63903275f86b

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

Attribution

Thanks Tomas Keech (Sentrium Security Ltd) for reporting this vulnerability.