CVE-2023-37908 org.xwiki.rendering:xwiki-rendering-xml Improper Neutralization of Invalid Characters in Identifiers in Web Pages vulnerability

What is CVE-2023-37908?

CVE-2023-37908 is a critical cross-site scripting vulnerability in xwiki-rendering, published on 25 Oct 2023. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

XWiki Rendering is a generic Rendering system that converts textual input in a given syntax into another syntax. The cleaning of attributes during XHTML rendering, introduced in version 14.6-rc-1, allowed the injection of arbitrary HTML code and thus cross-site scripting via invalid attribute names. This can be exploited, e.g., via the link syntax in any content that supports XWiki syntax like comments in XWiki. When a user moves the mouse over a malicious link, the malicious JavaScript code is executed in the context of the user session. When this user is a privileged user who has programming rights, this allows server-side code execution with programming rights, impacting the confidentiality, integrity and availability of the XWiki instance. While this attribute was correctly recognized as not allowed, the attribute was still printed with a prefix `data-xwiki-translated-attribute-` without further cleaning or validation. This problem has been patched in XWiki 14.10.4 and 15.0 RC1 by removing characters not allowed in data attributes and then validating the cleaned attribute again. There are no known workarounds apart from upgrading to a version including the fix.

Weakness: CWE-79, CWE-83

Which versions are affected by CVE-2023-37908?

2 open source packages ship an affected version, including org.xwiki.rendering:xwiki-rendering-xml. It affects 1 product.

Products include Xwiki Xwiki-Rendering.

How do I fix CVE-2023-37908?

Upgrade org.xwiki.rendering:xwiki-rendering-xml to 14.10.4 or later.

Escape output for the context it lands in and set a strict Content Security Policy. Upgrading the affected component is the real fix. More about Cross-site scripting.

Is CVE-2023-37908 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2023-37908 exists.

Public exploit code: 1 proofs of concept on GitHub.

Other vulnerabilities in xwiki-rendering

• CVE-2023-37912 XWiki Rendering's footnote macro vulnerable to privilege escalation via the footnote macro Critical 10.0
• CVE-2025-66474 XWiki vulnerable to remote code execution through insufficient protection against {{/html}} injection High 8.7

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-663w-2xp3-5739.