Unveiling CVE-2025-65868: XXE Threat in eyoucms v1.7.1

Overview

This article provides a detailed analysis of CVE-2025-65868, a critical XML External Entity (XXE) injection vulnerability discovered in eyoucms version 1.7.1. This vulnerability allows remote attackers to potentially cause a denial-of-service (DoS) condition by exploiting the CMS’s XML parsing capabilities. Understanding the technical details, potential impact, and available mitigation strategies is crucial for securing eyoucms installations.

Technical Details

CVE-2025-65868 stems from insufficient input validation when processing XML data submitted through POST requests in eyoucms v1.7.1. An attacker can craft a malicious XML payload containing an external entity declaration that references a local or remote resource. When the CMS parses this XML, it attempts to resolve the external entity, potentially leading to a denial of service. The specific endpoint and parameter vulnerable to this XXE attack require further investigation based on the vulnerable code in eyoucms v1.7.1. However, the core issue lies in the insecure handling of XML external entities.

An example of a potentially malicious XML payload could be:

            <?xml version="1.0"?>
            <!DOCTYPE foo [
             <!ENTITY xxe SYSTEM "file:///dev/random">
            ]>
            <foo>
              <bar>&xxe;</bar>
            </foo>
        

This example attempts to read the `/dev/random` file. In a successful XXE attack, this could lead to the server becoming unresponsive or crashing, causing a denial of service.

CVSS Analysis

The CVSS score for CVE-2025-65868 is currently marked as “N/A.” While the description indicates a denial-of-service vulnerability, a proper CVSS score will depend on the exploitability metrics (attack vector, attack complexity, privileges required, user interaction, scope, confidentiality impact, integrity impact, and availability impact). Once a CVSS score is assigned, it will provide a better indication of the severity of this vulnerability. It is likely the CVSS score would be high due to the potential for DoS.

Possible Impact

Successful exploitation of CVE-2025-65868 can lead to the following consequences:

• Denial of Service (DoS): The primary impact is the potential to render the eyoucms application unavailable, disrupting services for legitimate users.
• Potential for further exploitation: Depending on server configuration and permissions, XXE vulnerabilities can sometimes be chained with other vulnerabilities or exploited to leak sensitive information, although this is not explicitly stated in the CVE description.

Mitigation or Patch Steps

To address CVE-2025-65868, the following mitigation steps are recommended:

• Upgrade eyoucms: The most effective solution is to upgrade to a patched version of eyoucms if one is available. Check the eyoucms website for security updates.
• Disable external entity processing: If upgrading is not immediately feasible, configure the XML parser used by eyoucms to disable the processing of external entities. This is the most direct approach to prevent XXE attacks. Consult the documentation for the specific XML parser used (e.g., PHP’s `libxml`). For instance, if the application uses PHP, you might be able to use:

                      libxml_disable_entity_loader(true);
                  

• Input Validation: Implement strict input validation to sanitize any XML data received by the application. While less effective than disabling external entities, it can provide an additional layer of defense.
• Web Application Firewall (WAF): Employ a WAF with rules designed to detect and block XXE attacks. This can provide a temporary solution while more permanent fixes are implemented.

References

• CVE-2025-65868: CVE Record (This link will be live when CVE is published)
• eyoucms Issue: https://github.com/weng-xianhu/eyoucms/issues/66
• OWASP XXE Prevention: https://owasp.org/www-project-top-ten/2017/A4_2017-XML_External_Entities_(XXE)