Summary
org.xwiki.rendering:xwiki-rendering-xml Improper Neutralization of Invalid Characters in Identifiers in Web Pages vulnerability
Workarounds
There are no known workarounds apart from upgrading to a version including the fix.
References
- https://jira.xwiki.org/browse/XRENDERING-697
- https://github.com/xwiki/xwiki-rendering/commit/f4d5acac451dccaf276e69f0b49b72221eef5d2f
For more information
If you have any questions or comments about this advisory:
- Open an issue in Jira XWiki
- Email us at XWiki Security mailing-list
Impact
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:
[[Link1>>https://XWiki.example.com||/onmouseover="alert('XSS1')"]]
When a user moves the mouse over this 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.
Note that while versions below 14.6 are not vulnerable to this particular vulnerability, they are still vulnerable to XSS through attributes in XWiki syntax, see the corresponding advisory.
Untrusted input is rendered as active markup in a victim's browser, which can run script in their session. Typical impact: session or credential theft, and actions taken as the user.
CVE-2023-37908 has a CVSS score of 9.6 (Critical). The vector is network-reachable, no privileges required, and user interaction required. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (14.10.4); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
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.
Frequently Asked Questions
- What is CVE-2023-37908? CVE-2023-37908 is a critical-severity cross-site scripting (XSS) vulnerability in org.xwiki.rendering:xwiki-rendering-xml (maven), affecting versions >= 14.6-rc-1, < 14.10.4. It is fixed in 14.10.4. Untrusted input is rendered as active markup in a victim's browser, which can run script in their session.
- How severe is CVE-2023-37908? CVE-2023-37908 has a CVSS score of 9.6 (Critical). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of org.xwiki.rendering:xwiki-rendering-xml are affected by CVE-2023-37908? org.xwiki.rendering:xwiki-rendering-xml (maven) versions >= 14.6-rc-1, < 14.10.4 is affected.
- Is there a fix for CVE-2023-37908? Yes. CVE-2023-37908 is fixed in 14.10.4. Upgrade to this version or later.
- Is CVE-2023-37908 exploitable, and should I be worried? Whether CVE-2023-37908 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2023-37908 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2023-37908? Upgrade
org.xwiki.rendering:xwiki-rendering-xmlto 14.10.4 or later.