CVE-2025-4208 in NEX-Forms Plugin
Summary
by MITRE • 05/08/2025
The NEX-Forms – Ultimate Form Builder – Contact forms and much more plugin for WordPress is vulnerable to Limited Code Execution in all versions up to, and including, 8.9.1 via the get_table_records function. This is due to the unsanitized use of user-supplied input in call_user_func(). This makes it possible for authenticated attackers, with Custom-level access, to execute arbitrary PHP functions that meet specific constraints (static methods or global functions accepting a single array parameter).
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Analysis
by VulDB Data Team • 06/05/2025
The vulnerability identified as CVE-2025-4208 affects the NEX-Forms WordPress plugin, specifically targeting versions up to and including 8.9.1. This represents a significant security flaw that enables authenticated attackers with custom-level permissions to perform limited code execution within the WordPress environment. The vulnerability stems from improper input validation within the get_table_records function, which directly incorporates user-supplied data into PHP's call_user_func() mechanism without adequate sanitization. This flaw falls under CWE-74, which classifies improper neutralization of special elements in output used by a downstream component, specifically manifesting as improper sanitization of user input that ultimately leads to code execution.
The technical implementation of this vulnerability exploits the trust placed in user-supplied data within the plugin's core functionality. When the get_table_records function processes data, it accepts user input and passes it directly to call_user_func(), which then attempts to execute the specified PHP function. This creates a pathway for attackers to manipulate the function name parameter and execute arbitrary PHP code, though with specific constraints that limit the attack surface. The execution is restricted to static methods or global functions that accept a single array parameter, which narrows the potential attack vectors but still maintains significant risk. This vulnerability aligns with ATT&CK technique T1059.007, which covers execution through scripting languages, specifically targeting PHP code execution through function calls.
The operational impact of this vulnerability extends beyond simple code execution, as it provides attackers with a foothold for further exploitation within the WordPress environment. An authenticated attacker with custom-level access can leverage this vulnerability to perform actions such as data exfiltration, privilege escalation, or even complete system compromise if additional vulnerabilities exist. The constraint that limits execution to static methods or global functions with single array parameters means that attackers must carefully select their target functions, but this limitation does not prevent serious damage. The vulnerability demonstrates a critical flaw in input validation and sanitization practices, where user-supplied data flows directly into executable code paths without proper security checks.
Mitigation strategies for CVE-2025-4208 should prioritize immediate plugin updates to versions that address the vulnerability, as this represents the most effective defense against exploitation. Organizations should also implement network-level restrictions to limit access to the WordPress administration interface, particularly for users with custom-level permissions. Additionally, monitoring for suspicious function calls and unauthorized modifications to plugin files should be implemented as part of broader security operations. The vulnerability highlights the importance of proper input validation and the principle of least privilege, where user permissions should be carefully managed to minimize potential damage from compromised accounts. Security teams should also consider implementing web application firewalls that can detect and block malicious function calls targeting known vulnerable patterns within the plugin's codebase.