CVE-2022-0888 in File Uploads Extension Plugin
Summary
by MITRE • 03/24/2022
The Ninja Forms - File Uploads Extension WordPress plugin is vulnerable to arbitrary file uploads due to insufficient input file type validation found in the ~/includes/ajax/controllers/uploads.php file which can be bypassed making it possible for unauthenticated attackers to upload malicious files that can be used to obtain remote code execution, in versions up to and including 3.3.0
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Analysis
by VulDB Data Team • 04/08/2026
The vulnerability identified as CVE-2022-0888 affects the Ninja Forms - File Uploads Extension WordPress plugin, representing a critical security flaw that exposes systems to remote code execution risks. This vulnerability exists within the plugin's file upload functionality and specifically targets the ~/includes/ajax/controllers/uploads.php file where inadequate validation mechanisms fail to properly restrict file types. The flaw allows unauthenticated attackers to bypass security controls and upload malicious files to the target system, creating a severe attack surface that can be exploited without requiring any valid credentials or authentication.
The technical implementation of this vulnerability stems from insufficient input validation within the file upload processing logic. When users attempt to upload files through the plugin's interface, the system fails to properly validate the file extensions, MIME types, or file contents against a comprehensive whitelist of acceptable formats. This weakness enables attackers to upload files with potentially dangerous extensions such as .php, .jsp, or other server-side script formats that can execute code on the web server. The vulnerability operates at the application layer and specifically targets the plugin's AJAX upload controller, which handles file upload requests without adequate sanitization or verification processes.
From an operational perspective, this vulnerability presents a significant threat to WordPress installations running affected versions of the Ninja Forms plugin. Attackers can leverage this flaw to upload web shells, malware, or other malicious payloads that can establish persistent access to the compromised system. The remote code execution capability allows adversaries to execute arbitrary commands on the target server, potentially leading to complete system compromise, data exfiltration, or use as a foothold for further attacks within the network infrastructure. The impact extends beyond individual plugin functionality to potentially affect entire WordPress installations and underlying server environments.
Security mitigation strategies for CVE-2022-0888 should prioritize immediate plugin updates to versions that address the file validation vulnerability, as this represents the most effective remediation approach. Organizations should implement additional defensive measures including restricting file upload capabilities, implementing strict file type whitelisting, and deploying web application firewalls to monitor and block suspicious upload attempts. The vulnerability aligns with CWE-434 which describes insecure file upload vulnerabilities, and corresponds to ATT&CK technique T1190 for exploiting vulnerabilities in web applications. Regular security audits of WordPress plugins and automated vulnerability scanning should be implemented to identify similar issues in other installed components. System administrators should also consider implementing network segmentation and monitoring for unusual file upload activities to detect potential exploitation attempts.