CVE-2019-14794 in Meta Box Plugin
Summary
by MITRE
The Meta Box plugin before 4.16.2 for WordPress mishandles the uploading of files to custom folders.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 11/23/2023
The vulnerability identified as CVE-2019-14794 affects the Meta Box plugin version 4.16.1 and earlier for WordPress, representing a critical security flaw in file handling mechanisms. This issue stems from improper validation and sanitization of file upload processes within the plugin's custom folder functionality. The vulnerability allows authenticated attackers with sufficient privileges to upload arbitrary files to designated directories, potentially leading to remote code execution or other malicious activities. The flaw specifically manifests when the plugin processes file uploads to custom folders, where it fails to adequately verify the file types and content, creating an exploitable condition that undermines the security posture of affected WordPress installations.
The technical implementation of this vulnerability resides in the plugin's file upload handling code, which lacks proper input validation and access control mechanisms. When users upload files through the Meta Box plugin interface, the system should validate file extensions, MIME types, and content signatures to prevent malicious file infiltration. However, the vulnerable implementation bypasses these critical security checks, allowing attackers to upload files with potentially harmful extensions or content. This weakness aligns with CWE-434, which describes insecure file upload vulnerabilities where applications fail to properly validate or sanitize uploaded files. The vulnerability creates a path for attackers to execute arbitrary code on the target system by uploading malicious files such as web shells or scripts that can be executed within the web server context.
The operational impact of this vulnerability extends beyond simple file upload manipulation, as it provides attackers with potential persistence mechanisms and escalation capabilities within compromised WordPress environments. An attacker who gains access to a WordPress site with this vulnerability can upload malicious files to custom folders, potentially bypassing standard security controls and gaining unauthorized access to system resources. The vulnerability affects WordPress installations where the Meta Box plugin is active, particularly those with administrative or editor-level user accounts that have permission to upload files through the plugin interface. This creates a significant risk for organizations relying on WordPress for content management, as the attack surface expands to include all custom folder configurations that utilize the vulnerable plugin functionality. The impact is further amplified by the fact that WordPress installations often host sensitive data and may serve as entry points for broader network infiltration attempts.
Mitigation strategies for CVE-2019-14794 primarily focus on immediate plugin updates to version 4.16.2 or later, which contain the necessary patches to address the file upload validation issues. Organizations should implement comprehensive security monitoring to detect unauthorized file uploads and maintain regular vulnerability assessments of their WordPress installations. Additional protective measures include restricting file upload permissions, implementing strict file type validation, and employing web application firewalls to filter suspicious upload requests. The ATT&CK framework categorizes this vulnerability under T1190, which describes exploiting vulnerabilities in web applications, and T1059, which covers command and scripting interpreters. Security teams should also consider implementing principle of least privilege access controls for WordPress user accounts, particularly those with plugin management capabilities, to limit the potential impact of successful exploitation attempts. Regular security audits and patch management procedures should be enforced to prevent similar vulnerabilities from emerging in other WordPress plugins or core components.