CVE-2019-25734 in Contact Form Maker
Summary
by MITRE • 06/04/2026
Contact Form by WD 1.13.1 contains a cross-site request forgery vulnerability combined with local file inclusion that allows unauthenticated attackers to include arbitrary files by exploiting unsanitized action parameters. Attackers can craft malicious forms targeting the admin-ajax.php endpoint with directory traversal sequences in the GET action parameter to load files via CSRF, bypassing authentication on vulnerable AJAX actions.
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Analysis
by VulDB Data Team • 06/04/2026
The vulnerability in Contact Form by WD version 1.13.1 represents a critical security flaw that combines cross-site request forgery with local file inclusion capabilities, creating a severe attack vector for unauthenticated threat actors. This vulnerability resides within the plugin's handling of AJAX requests and specifically targets the admin-ajax.php endpoint which serves as a central communication point for WordPress administrative functions. The flaw stems from insufficient input validation and sanitization of the action parameter, allowing malicious actors to manipulate the request flow and execute unauthorized operations.
The technical implementation of this vulnerability exploits the lack of proper authentication checks and parameter sanitization within the plugin's AJAX handling mechanism. When attackers craft malicious requests with directory traversal sequences in the GET action parameter, they can manipulate the system to include arbitrary local files through the admin-ajax.php endpoint. This occurs because the plugin fails to properly validate or sanitize user-supplied input before processing it, creating an opportunity for path traversal attacks that bypass the normal authentication mechanisms. The vulnerability specifically affects AJAX actions that should require administrative privileges but are accessible through CSRF attacks due to the absence of proper nonce validation or session verification.
The operational impact of this vulnerability extends beyond simple file inclusion, as it enables attackers to gain unauthorized access to sensitive system resources and potentially execute arbitrary code. By leveraging the CSRF component, attackers can trick administrators into executing malicious requests without their knowledge, while the LFI component allows them to read system files, including configuration files that may contain database credentials or other sensitive information. This dual nature of the vulnerability creates a particularly dangerous attack scenario where threat actors can both escalate privileges and extract confidential data from the affected system. The attack requires no prior authentication, making it especially concerning for WordPress installations that rely on plugins for contact form functionality.
Security mitigations for this vulnerability should focus on implementing proper input validation and sanitization measures for all parameters passed to AJAX endpoints. The plugin should enforce strict authentication checks and implement nonce verification for all administrative actions, ensuring that requests originate from legitimate sources. Additionally, developers should implement proper file access controls and sanitize all user-supplied input to prevent directory traversal attacks. Organizations should also consider implementing web application firewalls that can detect and block suspicious patterns in AJAX requests targeting admin-ajax.php endpoints. The vulnerability aligns with CWE-79 (Cross-Site Scripting) and CWE-22 (Path Traversal) classifications, and represents a technique that could be categorized under ATT&CK tactic TA0001 (Initial Access) and technique T1566 (Phishing with Malicious Attachment) when used in conjunction with social engineering attacks. Regular security audits and prompt patch management are essential to prevent exploitation of such vulnerabilities in production environments.