| Package | Affected versions | Patched versions |
|---|---|---|
| org.xwiki.commons:xwiki-commons-xml | ≥ 4.2-milestone-1, < 14.10 | 14.10 |
| commons | = 4.2≥ 4.3, < 14.10 | 14.10 |
The "restricted" mode of the HTML cleaner in XWiki, introduced in version 4.2-milestone-1 and massively improved in version 14.6-rc-1, allowed the injection of arbitrary HTML code and thus cross-site scripting via invalid HTML comments. As a consequence, any code relying on this "restricted" mode for security is vulnerable to JavaScript injection ("cross-site scripting"/XSS). An example are anonymous comments in XWiki where the HTML macro filters HTML using restricted mode:
{{html}}
<!--> <Details Open OnToggle=confirm("XSS")>
{{/html}}
When a privileged user with programming rights visits such a comment in XWiki, the malicious JavaScript code is executed in the context of the user session. This allows server-side code execution with programming rights, impacting the confidentiality, integrity and availability of the XWiki instance.
Note that while all versions since 4.2-milestone-1 should be vulnerable, only starting with version 14.6-rc-1 the HTML comment is necessary for the attack to succeed due to another vulnerability that has been patched in version 14.6-rc-1.
This problem has been patched in XWiki 14.10, HTML comments are now removed in restricted mode and a check has been introduced that ensures that comments don't start with >.
There are no known workarounds apart from upgrading to a version including the fix.
If you have any questions or comments about this advisory:
This vulnerability was reported on Intigriti by ynoof @Ynoof5.
Running one of these products? Scan your site to see whether it exposes a vulnerable version.
Scan my site free