CVE-2017-14763 in GeniXCMS
Summary
by MITRE
In the Install Themes page in GeniXCMS 1.1.4, remote authenticated users can execute arbitrary PHP code via a .php file in a ZIP archive of a theme.
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Analysis
by VulDB Data Team • 11/20/2019
The vulnerability identified as CVE-2017-14763 represents a critical remote code execution flaw in GeniXCMS version 1.1.4 that specifically targets the theme installation functionality. This issue occurs within the Install Themes page where the application fails to properly validate or sanitize file uploads, creating an avenue for malicious actors to compromise the system. The vulnerability is particularly dangerous because it allows authenticated users to upload and execute arbitrary PHP code through a carefully crafted ZIP archive containing malicious files, effectively bypassing normal security controls that would typically prevent such execution.
The technical root cause of this vulnerability stems from inadequate input validation and improper file handling during the theme installation process. When users upload theme packages through the ZIP archive mechanism, the system does not adequately verify the contents of the archive or enforce strict file type restrictions. This allows attackers to include PHP files within the ZIP archive that will be executed during the extraction or installation process. The flaw falls under CWE-434 which specifically addresses "Unrestricted Upload of File with Dangerous Type" and represents a classic example of insecure file upload handling that enables arbitrary code execution. The vulnerability demonstrates a failure in the principle of least privilege and input sanitization that should be fundamental to any content management system.
The operational impact of this vulnerability is severe and multifaceted, as it enables attackers to gain full control over the compromised GeniXCMS instance. Once exploited, the malicious PHP code can be executed with the privileges of the web server, potentially allowing attackers to modify website content, steal sensitive data, install backdoors, or use the compromised system as a launchpad for further attacks. The authenticated nature of the vulnerability means that attackers need valid user credentials, but this requirement is often easily met through credential theft, social engineering, or other means. This vulnerability directly aligns with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: PowerShell" and T1078.004 for "Valid Accounts: Default Accounts" when considering the typical attack vectors that lead to authenticated access.
The exploitation process involves creating a malicious ZIP archive containing PHP files that will be executed when the theme installation process extracts and processes the contents. The vulnerability affects not just the immediate execution environment but can also impact the broader network infrastructure if the compromised CMS is part of a larger web ecosystem. Organizations using GeniXCMS 1.1.4 should immediately implement mitigations including disabling the theme upload functionality, implementing strict file validation mechanisms, and ensuring proper access controls are in place. Additionally, regular security audits and updates should be performed to prevent similar vulnerabilities from being introduced in future versions. The vulnerability highlights the critical importance of proper file validation and the principle of defense in depth when implementing web application security controls.