9 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality Impact
HIGH
Integrity Impact
HIGH
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
0.003 Low
EPSS
Percentile
70.5%
The “restricted” mode of the HTML cleaner in XWiki, introduced in version 4.2-milestone-1, only escaped <script>
and <style>
-tags but neither attributes that can be used to inject scripts nor other dangerous HTML tags like <iframe>
. 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}}
<a href>XSS</a>
{{/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.
This problem has been patched in XWiki 14.6 RC1 with the introduction of a filter with allowed HTML elements and attributes that is enabled in restricted mode.
There are no known workarounds apart from upgrading to a version including the fix.
If you have any questions or comments about this advisory:
github.com/xwiki/xwiki-commons
github.com/xwiki/xwiki-commons/commit/4a185e0594d90cd4916d60aa60bb4333dc5623b2
github.com/xwiki/xwiki-commons/commit/b11eae9d82cb53f32962056b5faa73f3720c6182
github.com/xwiki/xwiki-commons/security/advisories/GHSA-m3jr-cvhj-f35j
jira.xwiki.org/browse/XCOMMONS-1680
jira.xwiki.org/browse/XCOMMONS-2426
jira.xwiki.org/browse/XWIKI-9118
nvd.nist.gov/vuln/detail/CVE-2023-29201