CVE-2019-9050 in Pluck
Summary
by MITRE
An issue was discovered in Pluck 4.7.9-dev1. It allows administrators to execute arbitrary code by using action=installmodule to upload a ZIP archive, which is then extracted and executed.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 07/19/2023
The vulnerability identified as CVE-2019-9050 represents a critical remote code execution flaw within the Pluck content management system version 4.7.9-dev1. This issue stems from inadequate input validation and improper handling of user-supplied data during the module installation process. The vulnerability specifically manifests when administrators utilize the action=installmodule functionality to upload ZIP archives containing malicious payloads. The flaw allows attackers to bypass security measures and execute arbitrary code on the target system with the privileges of the web application.
This vulnerability falls under the category of insecure deserialization and improper input validation as classified by CWE-434, which specifically addresses the dangerous practice of accepting untrusted data without proper sanitization. The technical implementation flaw occurs in the module installation mechanism where the system fails to properly validate the contents of uploaded ZIP archives before extraction and execution. The system assumes that all uploaded modules are legitimate and trustworthy, creating a path for malicious actors to inject executable code directly into the web server environment.
The operational impact of this vulnerability is severe and multifaceted. An attacker who gains administrative access or can exploit this vulnerability to achieve administrative privileges can execute arbitrary commands on the target system. This capability enables full system compromise, data exfiltration, lateral movement within the network, and potential establishment of persistent backdoors. The vulnerability affects the entire Pluck installation, potentially exposing all content, user data, and system resources to unauthorized access. The remote nature of the exploit means that attackers can leverage this vulnerability from anywhere on the internet without requiring physical access to the system.
The attack surface for this vulnerability is particularly concerning as it targets the administrative functionality of the CMS, which typically requires elevated privileges to access. The exploitation process involves uploading a malicious ZIP archive containing a payload that gets executed during the module installation process. This approach aligns with ATT&CK technique T1059.001 for command and scripting interpreter, where adversaries use legitimate system tools to execute malicious code. Organizations using Pluck 4.7.9-dev1 should immediately implement mitigations including disabling the module installation functionality, implementing strict file type validation, and ensuring proper access controls are in place. The recommended remediation includes upgrading to a patched version of Pluck, implementing web application firewalls, and conducting thorough security audits of all uploaded content to prevent exploitation attempts.
Security practitioners should note that this vulnerability demonstrates the importance of principle of least privilege and proper input validation in web applications. The flaw represents a classic example of how insufficient validation of user-supplied data can lead to catastrophic consequences in content management systems. Organizations should implement comprehensive security measures including regular security updates, code reviews, and penetration testing to identify similar vulnerabilities in their web applications. The vulnerability also highlights the need for proper sandboxing of user uploads and the implementation of automated threat detection systems to identify malicious activity patterns.