CVE-2020-24141 in WP-DownloadManager Plugin
Summary
by MITRE • 07/07/2021
Server-side request forgery in the WP-DownloadManager plugin 1.68.4 for WordPress lets an attacker send crafted requests from the back-end server of a vulnerable web application via the file_remote parameter to download-add.php. It can help identify open ports, local network hosts and execute command on services
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Analysis
by VulDB Data Team • 07/10/2021
The vulnerability CVE-2020-24141 represents a critical server-side request forgery flaw in the WP-DownloadManager plugin for WordPress, specifically affecting version 1.68.4. This vulnerability resides within the download-add.php file and exploits the file_remote parameter to enable attackers to send malicious requests from the backend server of vulnerable web applications. The flaw stems from inadequate input validation and sanitization mechanisms that fail to properly restrict the URLs or resources that can be accessed through the plugin's file download functionality. According to CWE-918, this vulnerability falls under server-side request forgery, which is a well-documented class of security flaws where attackers can manipulate a server into making unintended requests to internal or external systems. The attack vector leverages the plugin's legitimate file download capabilities to extend beyond their intended scope, creating a dangerous pathway for unauthorized network reconnaissance and exploitation.
The technical implementation of this vulnerability allows attackers to leverage the vulnerable plugin's file_remote parameter to perform unauthorized requests to internal network resources that the backend server can access. When an attacker submits a crafted request through the download-add.php endpoint, the server processes the request without proper validation, potentially enabling access to internal services, open ports, or network hosts that would normally be protected by firewalls or network segmentation. The vulnerability can be exploited to perform port scanning activities, identify internal network hosts, and potentially execute commands against services running on those hosts. This capability significantly expands the attack surface beyond what would typically be accessible from the internet-facing web application, as the backend server's network access privileges are inadvertently exposed to malicious actors. The flaw demonstrates a classic lack of proper access control and input validation that aligns with ATT&CK technique T1190, which describes server-side request forgery as a method for bypassing access controls and gaining access to internal resources.
The operational impact of CVE-2020-24141 extends beyond simple information disclosure, as it provides attackers with a powerful tool for network reconnaissance and lateral movement within compromised environments. Once an attacker successfully exploits this vulnerability, they can map internal network topology, identify running services, and potentially escalate their attack to compromise additional systems. The ability to execute commands on services through this vector means that the vulnerability can serve as a stepping stone for more sophisticated attacks, including privilege escalation, data exfiltration, or the installation of persistent backdoors. Organizations running vulnerable WordPress installations with the WP-DownloadManager plugin face significant risk, as this vulnerability can be exploited by attackers with minimal technical expertise. The attack requires only a properly crafted HTTP request to the vulnerable plugin endpoint, making it particularly dangerous for organizations that do not maintain proper network segmentation or have robust web application firewalls in place to detect and block such malicious requests.
Mitigation strategies for CVE-2020-24141 should focus on immediate plugin updates to versions that address the vulnerability, as well as implementing network-level protections to prevent unauthorized access to internal resources. Organizations should ensure that all WordPress installations are regularly updated and that plugins are kept current with security patches. Network segmentation and proper firewall rules should be implemented to limit the backend server's access to internal resources, reducing the potential impact of such vulnerabilities. Web application firewalls can be configured to detect and block requests containing suspicious patterns in the file_remote parameter, providing an additional layer of protection. Additionally, organizations should implement proper input validation and sanitization for all user-supplied data, particularly parameters that interact with external resources or network services. Security monitoring should include detection of unusual network traffic patterns that might indicate port scanning or other reconnaissance activities initiated through the vulnerable plugin. The vulnerability highlights the importance of maintaining comprehensive security practices including regular vulnerability assessments, secure coding practices, and maintaining up-to-date security controls to protect against server-side request forgery attacks that can compromise entire network infrastructures.