CVE-2020-20919 in Pluck
Summary
by MITRE • 06/20/2023
File upload vulnerability in Pluck CMS v.4.7.10-dev2 allows a remote attacker to execute arbitrary code and access sensitive information via the theme.php file.
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Analysis
by VulDB Data Team • 12/10/2024
The vulnerability CVE-2020-20919 represents a critical file upload flaw in Pluck CMS version 4.7.10-dev2 that exposes the application to remote code execution and information disclosure attacks. This vulnerability specifically targets the theme.php file, which serves as a critical component for theme management within the content management system. The flaw enables authenticated attackers with sufficient privileges to upload malicious files that can subsequently be executed on the target server, creating a persistent backdoor for further exploitation. The vulnerability stems from inadequate input validation and sanitization mechanisms within the file upload functionality, allowing attackers to bypass security restrictions and upload arbitrary code.
The technical implementation of this vulnerability aligns with CWE-434, which describes insecure file upload handling where applications fail to properly validate or sanitize file types and contents before storage. The attack vector involves an authenticated user submitting a specially crafted file through the theme.php interface, which lacks proper file extension checks, content type validation, or secure storage mechanisms. This weakness creates a direct pathway for attackers to execute malicious code with the privileges of the web application, potentially leading to complete system compromise. The vulnerability is particularly dangerous because it leverages legitimate administrative functionality to facilitate malicious operations, making detection more challenging.
The operational impact of CVE-2020-20919 extends beyond simple code execution to include comprehensive information disclosure and system compromise capabilities. Successful exploitation allows attackers to gain unauthorized access to sensitive data, including user credentials, database information, and system files. The vulnerability can be exploited through various attack techniques that map to multiple ATT&CK tactics including initial access through credential compromise, execution via malicious file upload, privilege escalation by leveraging administrative privileges, and persistence through backdoor establishment. Organizations running affected Pluck CMS versions face significant risk of data breaches, service disruption, and potential regulatory compliance violations due to the exposure of sensitive information and unauthorized system access.
Mitigation strategies for CVE-2020-20919 should prioritize immediate patching of the affected Pluck CMS version to the latest stable release that addresses the file upload validation issues. Security administrators should implement restrictive file upload policies that enforce strict content type validation, implement proper file extension filtering, and ensure uploaded files are stored outside the web root directory. Network-based mitigations include implementing web application firewalls to monitor and block suspicious file upload requests, while host-based solutions should focus on file integrity monitoring and access control restrictions. Additionally, organizations should conduct comprehensive security assessments of their CMS environments, review user privilege assignments, and implement multi-factor authentication to reduce the attack surface. Regular security updates, vulnerability scanning, and security awareness training for administrators are essential components of a comprehensive defense strategy against similar vulnerabilities.