CVE-2020-37149: Edimax EW-7438RPn CSRF Vulnerability

CVE-2020-37149 Overview

CVE-2020-37149 is a Cross-Site Request Forgery (CSRF) vulnerability affecting the Edimax EW-7438RPn-v3 Mini Wi-Fi range extender running firmware version 1.27. This vulnerability allows attackers to trick authenticated users into submitting malicious requests that can lead to arbitrary command execution on the device. The flaw exists in the /goform/mp endpoint, which fails to implement proper CSRF protection mechanisms.

Critical Impact

Successful exploitation of this vulnerability enables attackers to execute arbitrary commands on the Edimax device with the privileges of the authenticated user, potentially leading to full device compromise, network infiltration, or use of the device in botnet operations.

Affected Products

• Edimax EW-7438RPn-v3 Mini firmware version 1.27
• Edimax N300 Wi-Fi Range Extender series

Discovery Timeline

• 2026-02-05 - CVE-2020-37149 published to NVD
• 2026-02-05 - Last updated in NVD database

Technical Details for CVE-2020-37149

Vulnerability Analysis

This CSRF vulnerability stems from inadequate request validation in the Edimax EW-7438RPn-v3 Mini device's web management interface. The /goform/mp endpoint accepts and processes HTTP requests without verifying their origin or including anti-CSRF tokens. This design flaw allows attackers to craft malicious web pages that, when visited by an authenticated administrator, automatically submit forged requests to the device.

The vulnerability is particularly concerning because it chains with command execution capabilities. When an attacker successfully exploits the CSRF flaw, they can inject arbitrary system commands that execute with the privileges of the authenticated user session. This escalation from CSRF to command execution significantly amplifies the impact, transforming what might typically be a configuration change into full device compromise.

Root Cause

The root cause of CVE-2020-37149 is the absence of CSRF protection mechanisms in the device's web interface, specifically the /goform/mp endpoint. The firmware fails to implement industry-standard protections such as anti-CSRF tokens, same-origin policy enforcement, or referer header validation. Combined with insufficient input sanitization on command parameters, this allows the chained exploitation leading to command execution.

Attack Vector

The attack requires user interaction through a network-based vector. An attacker must entice an authenticated administrator to visit a malicious webpage while they have an active session with the Edimax device. The attacker's webpage contains a hidden form that automatically submits a crafted request to the /goform/mp endpoint on the target device.

The exploitation flow involves the attacker hosting a malicious webpage containing a hidden HTML form. When the victim, who is authenticated to the Edimax device, visits this webpage, the form auto-submits a request to the device's /goform/mp endpoint. The device processes the forged request as legitimate, executing any embedded commands with the user's privileges.

For technical exploitation details, refer to the Exploit-DB #48318 entry and the VulnCheck Advisory.

Detection Methods for CVE-2020-37149

Indicators of Compromise

• Unexpected HTTP POST requests to the /goform/mp endpoint from external referers
• Unusual command execution patterns or system calls originating from the web server process
• Web server logs showing requests to /goform/mp with suspicious or encoded command parameters
• Network traffic patterns indicating communication between the device and unknown external hosts

Detection Strategies

• Monitor HTTP request logs for POST requests to /goform/mp with suspicious referer headers indicating external origins
• Implement network-based intrusion detection rules to identify CSRF attack patterns targeting Edimax devices
• Deploy web application firewall rules to inspect and block requests lacking proper origin validation
• Analyze outbound traffic from Edimax devices for unexpected connections that may indicate post-exploitation activity

Monitoring Recommendations

• Enable verbose logging on the Edimax device's web interface to capture all administrative requests
• Configure network monitoring to alert on traffic anomalies involving the device's management ports
• Implement egress filtering to detect and block unauthorized outbound connections from IoT devices
• Regularly audit device configurations for unauthorized changes that may indicate successful exploitation

How to Mitigate CVE-2020-37149

Immediate Actions Required

• Restrict access to the Edimax device's web management interface to trusted networks only using firewall rules
• Disable remote management functionality if not strictly required for operations
• Implement network segmentation to isolate IoT devices from general user networks
• Educate users to avoid browsing untrusted websites while authenticated to network devices

Patch Information

No official patch information is available from Edimax at this time. Users should check the Edimax Product Page for firmware updates and security advisories. Consider replacing vulnerable devices with models that receive active security support if no patch becomes available.

Workarounds

• Deploy a reverse proxy or web application firewall in front of the device to add CSRF protection
• Configure access control lists (ACLs) to permit management interface access only from specific administrative workstations
• Implement browser isolation for administrative tasks to prevent cross-site attacks from affecting device sessions
• Consider deploying the device on an isolated VLAN with no direct internet access

# Network isolation example using iptables
# Restrict access to Edimax device management interface (port 80)
iptables -A FORWARD -d 192.168.1.100 -p tcp --dport 80 -s 192.168.1.10 -j ACCEPT
iptables -A FORWARD -d 192.168.1.100 -p tcp --dport 80 -j DROP