Description
The Everest Forms – Contact Form, Quiz, Survey, Newsletter & Payment Form Builder for WordPress plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 3.1.1 via deserialization of untrusted input from the 'field_value' parameter. This makes it possible for unauthenticated attackers to inject a PHP Object. No known POP chain is present in the vulnerable software, which means this vulnerability has no impact unless another plugin or theme containing a POP chain is installed on the site. If a POP chain is present via an additional plugin or theme installed on the target system, it may allow the attacker to perform actions like delete arbitrary files, retrieve sensitive data, or execute code depending on the POP chain present.
EPSS Score:
0%
Comprehensive Technical Analysis of EUVD-2025-10803
1. Vulnerability Assessment and Severity Evaluation
The vulnerability identified in the Everest Forms plugin for WordPress (EUVD-2025-10803) is a PHP Object Injection flaw. This vulnerability arises from the deserialization of untrusted input from the 'field_value' parameter, which can be exploited by unauthenticated attackers. The severity of this vulnerability is rated at a base score of 9.8 according to CVSS 3.1, indicating a critical risk. The vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H highlights the following:
- Attack Vector (AV): Network (N) - The vulnerability is exploitable over the network.
- Attack Complexity (AC): Low (L) - The attack requires minimal skill or resources.
- Privileges Required (PR): None (N) - No authentication is required to exploit the vulnerability.
- User Interaction (UI): None (N) - No user interaction is required.
- Scope (S): Unchanged (U) - The vulnerability does not change the security scope.
- Confidentiality (C): High (H) - There is a high impact on the confidentiality of the system.
- Integrity (I): High (H) - There is a high impact on the integrity of the system.
- Availability (A): High (H) - There is a high impact on the availability of the system.
2. Potential Attack Vectors and Exploitation Methods
The primary attack vector involves injecting a malicious PHP object through the 'field_value' parameter. Although the vulnerability itself does not contain a Property-Oriented Programming (POP) chain, the presence of a POP chain in another installed plugin or theme can significantly amplify the risk. Potential exploitation methods include:
- Arbitrary File Deletion: If a POP chain allows it, an attacker could delete critical system files.
- Sensitive Data Retrieval: An attacker could extract sensitive information from the server.
- Code Execution: If a suitable POP chain is present, an attacker could execute arbitrary code on the server.
3. Affected Systems and Software Versions
The vulnerability affects all versions of the Everest Forms plugin up to and including version 3.1.1. Any WordPress site using this plugin within the affected version range is at risk.
4. Recommended Mitigation Strategies
To mitigate this vulnerability, the following steps are recommended:
- Update the Plugin: Ensure that the Everest Forms plugin is updated to a version higher than 3.1.1, which addresses the vulnerability.
- Review Installed Plugins and Themes: Assess all installed plugins and themes for the presence of POP chains that could be exploited in conjunction with this vulnerability.
- Implement Input Validation: Ensure that all input parameters are properly validated and sanitized to prevent deserialization of untrusted data.
- Monitor and Log: Implement robust logging and monitoring to detect any suspicious activities related to the 'field_value' parameter.
- Regular Security Audits: Conduct regular security audits and vulnerability assessments to identify and address potential security issues.
5. Impact on European Cybersecurity Landscape
The vulnerability poses a significant risk to the European cybersecurity landscape, particularly for organizations and individuals using WordPress with the Everest Forms plugin. Given the widespread use of WordPress, the potential impact could be extensive, affecting various sectors including e-commerce, media, and government websites. The high severity score underscores the need for immediate attention and remediation to prevent potential data breaches and system compromises.
6. Technical Details for Security Professionals
- Vulnerability Type: PHP Object Injection via deserialization of untrusted input.
- Affected Parameter: 'field_value'
- Exploitation Conditions: Requires the presence of a POP chain in another installed plugin or theme.
- References:
Conclusion
The PHP Object Injection vulnerability in the Everest Forms plugin for WordPress is a critical issue that requires immediate attention. Organizations should prioritize updating the plugin and conducting thorough security assessments to mitigate the risk. The potential for severe impacts, including data breaches and system compromises, underscores the importance of proactive cybersecurity measures.