CVE-2015-9402 in users-ultra Plugin
Summary
by MITRE
The users-ultra plugin before 1.5.59 for WordPress has uultra-form-cvs-form-conf arbitrary file upload.
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Analysis
by VulDB Data Team • 12/27/2023
The CVE-2015-9402 vulnerability represents a critical arbitrary file upload flaw within the users-ultra plugin for WordPress systems. This vulnerability exists in versions prior to 1.5.59 and allows attackers to upload malicious files to the target system without proper authentication or authorization. The issue stems from insufficient input validation and sanitization within the plugin's file upload functionality, specifically in the uultra-form-cvs-form-conf component. Attackers can exploit this weakness to execute arbitrary code on the affected WordPress installation, potentially leading to complete system compromise.
The technical implementation of this vulnerability involves the plugin's failure to properly validate file extensions and content types during the upload process. The uultra-form-cvs-form-conf module lacks proper restrictions on file uploads, allowing malicious actors to bypass security measures that would normally prevent execution of potentially harmful files such as php, aspx, or other script files. This flaw falls under the CWE-434 category of Unrestricted Upload of File with Dangerous Type, which is a well-documented vulnerability pattern that directly enables malicious file execution. The vulnerability operates at the application layer and can be exploited through web-based interfaces, making it particularly dangerous for web applications that rely on user-uploaded content.
The operational impact of this vulnerability is severe and multifaceted. Successful exploitation can result in complete compromise of the WordPress installation, including unauthorized access to user data, potential data exfiltration, and the ability to establish persistent backdoors. Attackers can upload web shells or other malicious scripts that provide remote code execution capabilities, allowing them to perform actions such as modifying website content, stealing administrative credentials, or using the compromised system as a launchpad for further attacks within the network. The vulnerability also poses significant risks to the broader infrastructure since WordPress installations often serve as entry points for larger attack campaigns. This aligns with ATT&CK technique T1190 which describes the use of vulnerabilities to gain initial access to systems.
Mitigation strategies for CVE-2015-9402 primarily focus on immediate remediation and ongoing security hardening. The most effective solution is to upgrade the users-ultra plugin to version 1.5.59 or later, which includes proper file validation and sanitization measures. Additionally, administrators should implement strict file upload restrictions by configuring the web server to reject executable file types and by implementing Content Security Policies that prevent unauthorized file execution. Network-level protections such as web application firewalls can provide additional layers of defense by monitoring and blocking suspicious upload attempts. Security monitoring should include regular scanning for vulnerable plugins and maintaining up-to-date security patches across all WordPress components. Organizations should also implement principle of least privilege access controls and regularly audit their WordPress installations to identify and remediate similar vulnerabilities. The vulnerability demonstrates the critical importance of maintaining current plugin versions and implementing comprehensive security controls around file upload functionalities to prevent exploitation of such critical flaws.