XWiki Commons is a collection of technical libraries that serve as the foundation for various top-level XWiki projects. Among the many components of XWiki Commons, the RSS macro is a notable feature that enables the integration of RSS feeds into wiki pages. However, in versions up to XWiki 14.6 RC1, the RSS macro had a significant security vulnerability, allowing potential attackers to exploit cross-site scripting (XSS) and potentially execute arbitrary actions on the wiki.

The Vulnerability

The vulnerability in the RSS macro (CVE-2023-29202) stems from a failure to sanitize the content of feed items before incorporating them into HTML output when the content parameter is set to true. As a result, attackers could inject arbitrary HTML or JavaScript code into the RSS feed, leading to the exploitation of XSS.

Here's an example of a simple, yet potentially harmful, code snippet an attacker could inject into the RSS feed:

<script>alert("XSS Attack");</script>

Once this malicious code snippet is included in an RSS feed and displayed on a wiki page, it could trigger unwanted actions, such as pop-up alerts, redirections, or even the execution of malicious scripts that impact the user experience or compromise the security of sensitive information.

Exploitation Details

As mentioned earlier, the key factor that enables the exploitation of this vulnerability is the failure to properly clean the content of the RSS feed items. The XSS vulnerability can have severe consequences, especially when combined with the privileges of a user with programming rights, leading to the following risks:

1. Privilege Escalation - An attacker could potentially exploit the vulnerability to elevate their privileges within the wiki, granting them unauthorized access to sensitive information or allowing them to make changes to wiki content and configurations.
2. Remote Code Execution - With the ability to inject malicious scripts, an attacker could potentially execute arbitrary code on the target system, leading to a full-fledged compromise of the affected wiki.
3. Information Disclosure - Sensitive information in the wiki could be accessed by attackers exploiting the XSS vulnerability, jeopardizing the confidentiality of the data.
4. Modifying or Deleting Content - Attackers could potentially use their gained privileges to modify or delete wiki content, leading to data loss or corruption.
5. Wiki Sabotaging - Alongside modifying content, attackers could also disrupt the functionality of the wiki, causing denial of service or other adverse effects.

Mitigation and Patch

The issue has been addressed in XWiki 14.6 RC1, where the contents of the RSS feed are cleaned before being displayed. Users running an earlier version of XWiki are advised to upgrade as soon as possible to ensure protection against this vulnerability.

In the meantime, if the RSS macro is not in use, users can work around the issue by uninstalling the macro. To do so, navigate to the web application's directory (/webapps/xwiki) and delete the file WEB-INF/lib/xwiki-platform-rendering-macro-rss-XX.jar, where XX represents the version of XWiki currently installed.


- XWiki Commons
- XWiki RSS Macro
- XWiki Security Advisory (CVE-2023-29202)

To err on the side of caution, always ensure you are using the latest version of XWiki and its components. Keeping your software up-to-date is a key aspect of maintaining a secure and robust wiki environment. If you discover any other potential vulnerabilities, report them to the XWiki community so that they can be swiftly addressed and resolved.


Published on: 04/15/2023 15:15:00 UTC
Last modified on: 04/25/2023 18:55:00 UTC