CVE-2025-2689

Remediation/Mitigation Strategy for CVE-2025-2689: Yii2 Deserialization Vulnerability

This document outlines the remediation and mitigation strategies for CVE-2025-2689, a critical deserialization vulnerability found in Yii2.

1. Vulnerability Description

  • Vulnerability: Deserialization vulnerability in symfony\finder\Iterator\SortableIterator.php’s getIterator function within the Yii2 framework.
  • Affected Version: Yii2 up to version 2.0.45.
  • Attack Vector: Remote. An attacker can potentially exploit this vulnerability remotely.
  • Root Cause: Improper handling of user-supplied data leading to the deserialization of untrusted data. The vulnerability lies in the way getIterator handles input which, if crafted maliciously, can force PHP to deserialize an object in a dangerous way.
  • Impact: Successful exploitation can lead to Remote Code Execution (RCE), allowing the attacker to execute arbitrary code on the server. This can result in full system compromise, data breaches, and denial-of-service.

2. Severity

  • CVSS Score: 9.8 (Critical)
    • CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
  • Severity Level: Critical

3. Known Exploit

  • Publicly Available Exploit: An exploit for this vulnerability is publicly available, meaning attackers can readily leverage existing tools and techniques to exploit the vulnerability. This significantly increases the risk.
  • Exploit Details: The exploit likely involves crafting a malicious serialized object that, when deserialized by the vulnerable function, triggers arbitrary code execution. Specific exploit details are readily available due to its public nature.

4. Remediation Strategy

The primary goal of the remediation strategy is to eliminate the vulnerability completely.

  • Upgrade Yii2: The MOST IMPORTANT step is to upgrade Yii2 to a version greater than 2.0.45. This is the recommended and most effective approach. Check the Yii Framework website for the latest version and upgrade instructions.
  • Verify Upgrade: After the upgrade, thoroughly test the application to ensure the vulnerability is resolved and that no new issues have been introduced.

5. Mitigation Strategy

If upgrading immediately is not feasible, consider the following mitigation techniques, although they DO NOT provide complete protection:

  • Input Validation and Sanitization: Implement strict input validation and sanitization on all user-supplied data that is processed by the getIterator function or any related code paths. This will help prevent malicious serialized objects from being passed to the deserialization process. However, note that relying solely on input validation is generally insufficient to prevent deserialization attacks.
  • Disable Deserialization (Not Recommended unless absolutely necessary): While not ideal and can break functionality, you could temporarily disable deserialization altogether in the affected areas if possible and if the application’s functionalities allow it. This is a drastic measure and should only be considered as a last resort. It can be achieved using unserialize_callback_func or ini_set('session.serialize_handler', 'php_serialize'); but may cause errors in many Yii2 setups.
  • Web Application Firewall (WAF) Rules: Deploy a WAF with rules specifically designed to detect and block deserialization attacks. This can provide an additional layer of protection, but it is not a replacement for patching the vulnerability. Ensure the WAF rules are kept up-to-date. Look for rules designed to prevent the exploitation of CVE-2025-2689.
  • Monitor for Suspicious Activity: Implement robust monitoring and logging to detect any attempts to exploit the vulnerability. Look for unusual patterns in web server logs, PHP error logs, and network traffic that could indicate a deserialization attack.
  • Code Review: Conduct a thorough code review of the affected areas to identify any other potential vulnerabilities related to deserialization or other security issues.

6. Timeline

  • Immediate (within 24 hours):
    • Assess the impact of the vulnerability on your systems.
    • Implement immediate mitigation measures if possible (WAF rules, monitoring).
  • High Priority (within 72 hours):
    • Plan and schedule the Yii2 upgrade.
    • Begin testing the upgrade in a non-production environment.
  • Critical (within 1 week):
    • Deploy the Yii2 upgrade to production environments.
    • Verify that the vulnerability is resolved.
  • Ongoing:
    • Regularly review and update security practices.
    • Stay informed about new vulnerabilities and security updates for Yii2 and other software.

7. Communication

  • Inform relevant stakeholders (developers, system administrators, security team) about the vulnerability and the remediation plan.
  • Provide regular updates on the progress of the remediation efforts.

8. Testing

  • After implementing the remediation steps, perform thorough testing to ensure the vulnerability has been completely eliminated and that no new issues have been introduced. This should include both automated and manual testing.
  • Use penetration testing tools to simulate attacks and verify the effectiveness of the remediation efforts.

9. Disclaimer

This document provides general guidance on remediating and mitigating CVE-2025-2689. The specific steps required will vary depending on the specifics of your environment. It is recommended to consult with security experts for personalized advice.

Remember: Upgrading Yii2 is the most effective solution for this vulnerability.

Assigner

Date

  • Published Date: 2025-03-24 07:15:14
  • Updated Date: 2025-03-24 17:17:27

More Details

CVE-2025-2689