CVE-2023-6558 in Export and Import Users and Customers Plugin
Summary
by MITRE • 01/11/2024
The Export and Import Users and Customers plugin for WordPress is vulnerable to arbitrary file uploads due to insufficient file type validation on the 'upload_import_file' function in versions up to, and including, 2.4.8. This makes it possible for authenticated attackers with shop manager-level capabilities or above, to upload arbitrary files on the affected site's server which may make remote code execution possible.
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Analysis
by VulDB Data Team • 06/03/2025
The CVE-2023-6558 vulnerability affects the Export and Import Users and Customers plugin for WordPress, specifically targeting versions up to and including 2.4.8. This security flaw resides within the 'upload_import_file' function which fails to properly validate file types during the upload process. The vulnerability represents a critical weakness in the plugin's input sanitization mechanisms, creating an avenue for malicious exploitation that could compromise the entire WordPress installation. The flaw is particularly concerning because it requires only authenticated access with shop manager privileges or higher, making it accessible to users who already have significant control over the e-commerce platform.
The technical implementation of this vulnerability stems from inadequate validation of file extensions and content within the plugin's file upload functionality. Attackers can exploit this weakness by uploading malicious files such as php shells or web shells that bypass the standard WordPress security measures. The insufficient validation allows attackers to upload files with extensions that should be restricted, potentially including .php, .phtml, .php3, or other executable file types. This vulnerability aligns with CWE-434 which describes "Unrestricted Upload of File with Dangerous Type" and represents a classic path to remote code execution through file upload manipulation. The flaw operates at the application level where the plugin fails to properly filter and validate file attributes before storing them on the server filesystem.
The operational impact of CVE-2023-6558 extends beyond simple unauthorized file placement on the server. Once an attacker successfully uploads malicious files, they can execute arbitrary code on the affected WordPress installation, potentially leading to full system compromise. This vulnerability enables attackers to establish persistent access, modify or exfiltrate customer data, and use the compromised server as a launchpad for further attacks within the network. The attack surface is particularly dangerous in e-commerce environments where customer data, payment information, and business-critical data are stored. The vulnerability also aligns with ATT&CK technique T1190 "Exploit Public-Facing Application" and T1059.007 "Command and Scripting Interpreter: PowerShell" when attackers leverage the uploaded files for execution purposes.
Organizations affected by this vulnerability should immediately implement multiple layers of mitigation strategies. The primary recommendation involves upgrading to the latest version of the plugin where the file validation has been properly implemented. Additionally, administrators should restrict file upload capabilities to only essential user roles and implement strict file type filtering at both the application and server levels. Network-based mitigations including web application firewalls and intrusion detection systems can help detect and prevent exploitation attempts. The vulnerability demonstrates the critical importance of proper input validation and the principle of least privilege in web application security. Regular security audits and vulnerability assessments should be conducted to identify similar weaknesses in other plugins and themes, as this represents a common pattern in WordPress security vulnerabilities where insufficient validation leads to severe consequences.