CVE-2020-20718 in PluckCMS
Summary
by MITRE • 06/20/2023
File Upload vulnerability in PluckCMS v.4.7.10 dev versions allows a remote attacker to execute arbitrary code via a crafted image file to the the save_file() parameter.
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Analysis
by VulDB Data Team • 12/10/2024
The CVE-2020-20718 vulnerability represents a critical file upload flaw in PluckCMS version 4.7.10 development releases that exposes systems to remote code execution attacks. This vulnerability specifically targets the save_file() parameter within the content management system's file handling mechanisms, creating a pathway for malicious actors to bypass security controls and deploy arbitrary code on affected servers. The flaw stems from inadequate input validation and sanitization processes that fail to properly verify the authenticity and content of uploaded files, particularly image files that are commonly used for media content in web applications.
The technical exploitation of this vulnerability occurs when an attacker crafts a malicious image file that contains executable code or malicious payload disguised as legitimate media content. The save_file() parameter in PluckCMS does not adequately validate file types or content, allowing attackers to upload files that appear to be standard image formats such as jpg, png, or gif but actually contain malicious code. This type of vulnerability falls under the CWE-434 category, which specifically addresses "Unrestricted Upload of File with Dangerous Type," representing a well-documented weakness in web application security where applications fail to properly restrict file uploads to dangerous or executable formats. The vulnerability creates a direct pathway for attackers to execute arbitrary code on the target system with the privileges of the web application process, potentially leading to complete system compromise.
Operationally, this vulnerability poses significant risks to organizations using PluckCMS development versions, as it enables remote attackers to gain unauthorized access to server resources and execute malicious commands without requiring authentication. The impact extends beyond simple code execution to include potential data exfiltration, system persistence mechanisms, and lateral movement within network environments. Attackers can leverage this vulnerability to establish backdoors, install malware, or use the compromised system as a launching point for attacks against other networked systems. The threat landscape for such vulnerabilities is particularly concerning given that development versions of software often lack the comprehensive security testing and hardening measures applied to stable releases, making them prime targets for exploitation.
Organizations should immediately implement mitigation strategies including immediate patching of the PluckCMS installation to the latest stable release, implementing strict file type validation and content inspection for all uploaded files, and configuring web application firewalls to monitor and block suspicious file upload patterns. The vulnerability aligns with ATT&CK technique T1190, which covers "Exploit Public-Facing Application," and T1059, covering "Command and Scripting Interpreter," as attackers can leverage this flaw to execute commands and scripts on compromised systems. Additional protective measures include restricting file upload functionality to authenticated users only, implementing file content analysis tools to detect malicious payloads, and conducting regular security assessments to identify similar vulnerabilities in other web applications within the organization's infrastructure.