CVE-2017-14958 in PivotX
Summary
by MITRE
lib.php in PivotX 2.3.11 does not properly block uploads of dangerous file types by admin users, which allows remote PHP code execution via an upload of a .php file.
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Analysis
by VulDB Data Team • 11/21/2019
The vulnerability identified as CVE-2017-14958 resides within the PivotX content management system version 2.3.11 where the lib.php script fails to implement proper validation mechanisms for file uploads. This critical flaw affects administrative users who possess the ability to upload files to the system, creating a pathway for remote code execution through the deliberate upload of malicious php files. The vulnerability stems from insufficient input sanitization and file type validation processes that should have been enforced during the upload procedure.
This security weakness represents a classic example of insecure file upload functionality that directly maps to CWE-434, which defines the improper restriction of uploads of executable files. The flaw allows authenticated administrators to bypass the intended security controls that should prevent the upload of potentially dangerous file types including php scripts, executable binaries, or other malicious payloads. Attackers can exploit this by uploading a php shell or webshell that would execute with the privileges of the web server process, effectively granting them remote code execution capabilities within the target environment.
The operational impact of this vulnerability extends beyond simple code execution as it provides attackers with persistent access to the compromised system. Once a malicious php file is uploaded and executed, adversaries can establish backdoors, escalate privileges, exfiltrate sensitive data, or use the compromised system as a staging area for further attacks. The vulnerability is particularly dangerous because it leverages the legitimate administrative upload functionality, making the malicious activity appear as normal administrative operations within system logs and audit trails. This characteristic aligns with ATT&CK technique T1106 for execution through legitimate system processes and T1078 for valid accounts usage.
Mitigation strategies for this vulnerability require immediate implementation of multiple defense-in-depth measures including strict file type validation, content inspection, and proper file extension filtering. Organizations should implement whitelisting mechanisms that only permit specific, safe file extensions while rejecting potentially dangerous types such as .php, .phtml, .php3, .php4, .php5, .phar, .asp, .aspx, and others. Additionally, uploaded files should be stored outside the web root directory and renamed with unique identifiers to prevent direct access. The system should also enforce proper access controls, implement file content verification, and regularly scan uploaded files for malicious content. Security patches should be applied immediately to upgrade to versions of PivotX that address this vulnerability, as the flaw represents a critical security risk that could lead to complete system compromise and persistent unauthorized access.