CVE-2025-3439

Comprehensive Technical Analysis of CVE-2025-3439

1. Vulnerability Assessment and Severity Evaluation

CVE ID: CVE-2025-3439 CVSS Score: 9.8

The vulnerability in the Everest Forms plugin for WordPress is classified as a PHP Object Injection vulnerability. This type of vulnerability occurs due to the deserialization of untrusted input, specifically through the 'field_value' parameter. The severity of this vulnerability is rated at 9.8 on the CVSS scale, indicating a critical risk. The high score is justified by the potential for unauthenticated attackers to inject PHP objects, which can lead to severe consequences if a Property-Oriented Programming (POP) chain is present in other installed plugins or themes.

2. Potential Attack Vectors and Exploitation Methods

Attack Vectors:

• Unauthenticated Attack: The vulnerability can be exploited by unauthenticated attackers, meaning anyone with access to the WordPress site can attempt to exploit this flaw.
• Deserialization of Untrusted Input: The attacker can send crafted input to the 'field_value' parameter, which is then deserialized by the vulnerable plugin.

Exploitation Methods:

• PHP Object Injection: The attacker injects a malicious PHP object into the deserialization process.
• POP Chain Exploitation: If another plugin or theme with a POP chain is installed, the attacker can leverage this to perform actions such as deleting arbitrary files, retrieving sensitive data, or executing arbitrary code.

3. Affected Systems and Software Versions

Affected Software:

• Everest Forms – Contact Form, Quiz, Survey, Newsletter & Payment Form Builder for WordPress

Affected Versions:

• All versions up to and including 3.1.1

Platform:

• WordPress

4. Recommended Mitigation Strategies

Immediate Actions:

• Update the Plugin: Ensure that the Everest Forms plugin is updated to a version higher than 3.1.1, where the vulnerability has been patched.
• Disable the Plugin: If an update is not immediately available, consider disabling the plugin until a secure version is released.

Long-Term Mitigations:

• Regular Audits: Conduct regular security audits of all installed plugins and themes to identify and mitigate potential vulnerabilities.
• Least Privilege Principle: Ensure that only necessary plugins and themes are installed and that they are kept up to date.
• Web Application Firewall (WAF): Implement a WAF to monitor and block suspicious activities, including attempts to exploit deserialization vulnerabilities.

5. Impact on Cybersecurity Landscape

The discovery of CVE-2025-3439 highlights the ongoing risk associated with third-party plugins and themes in content management systems like WordPress. This vulnerability underscores the importance of:

• Regular Patching: Ensuring that all components of a web application are regularly updated.
• Code Review: Conducting thorough code reviews and security assessments of third-party components.
• Community Collaboration: Encouraging collaboration within the cybersecurity community to identify and mitigate vulnerabilities promptly.

6. Technical Details for Security Professionals

Vulnerability Details:

• Deserialization Process: The vulnerability arises from the deserialization of the 'field_value' parameter without proper validation or sanitization.
• POP Chain Requirement: The exploitability of this vulnerability depends on the presence of a POP chain in other installed plugins or themes. Without a POP chain, the impact is limited.

Code Analysis:

• Vulnerable Code: The deserialization process occurs in the file html-admin-page-entries-view.php at line 147.
• Patch: The vulnerability was addressed in changeset 3268742, which includes proper validation and sanitization of the 'field_value' parameter.

References:

• Everest Forms Plugin Code
• Patch Changeset
• Wordfence Threat Intelligence

Conclusion

CVE-2025-3439 represents a critical vulnerability in the Everest Forms plugin for WordPress. The potential for unauthenticated PHP Object Injection, coupled with the possibility of leveraging POP chains from other plugins or themes, makes this a high-risk issue. Immediate mitigation through plugin updates and long-term security practices are essential to protect against such vulnerabilities. The cybersecurity community must remain vigilant and proactive in identifying and addressing similar issues to maintain the integrity and security of web applications.