CVE-2024-41468: Tendacn Fh1201 Firmware RCE Vulnerability

CVE-2024-41468 Overview

CVE-2024-41468 is a command injection vulnerability discovered in the Tenda FH1201 wireless router firmware version 1.2.0.14. The vulnerability exists in the /goform/exeCommand endpoint, specifically through the cmdinput parameter, which allows remote attackers to execute arbitrary system commands on the affected device without authentication.

Critical Impact

This vulnerability enables unauthenticated remote attackers to execute arbitrary operating system commands on the Tenda FH1201 router, potentially leading to complete device compromise, network infiltration, and persistent access to the victim's network infrastructure.

Affected Products

• Tenda FH1201 Firmware version 1.2.0.14
• Tenda FH1201 Hardware Device

Discovery Timeline

• 2024-07-25 - CVE-2024-41468 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2024-41468

Vulnerability Analysis

This command injection vulnerability (CWE-78, CWE-94) resides in the web management interface of the Tenda FH1201 router. The /goform/exeCommand endpoint accepts user-supplied input through the cmdinput parameter without proper sanitization or validation. When malicious input containing shell metacharacters or command sequences is submitted, the router's firmware directly passes this input to the underlying operating system shell for execution.

The vulnerability is particularly dangerous because it requires no authentication to exploit, meaning any attacker with network access to the router's management interface can execute arbitrary commands with the privileges of the web server process, which typically runs as root on embedded devices like this.

Root Cause

The root cause of this vulnerability is insufficient input validation and improper neutralization of special elements used in OS command construction. The cmdinput parameter in the /goform/exeCommand handler does not sanitize shell metacharacters such as semicolons (;), pipes (|), backticks (`), or command substitution syntax ($()). This allows attackers to break out of the intended command context and inject arbitrary commands.

Attack Vector

The attack vector is network-based, targeting the router's web management interface. An attacker can craft malicious HTTP requests to the /goform/exeCommand endpoint with specially constructed cmdinput values containing shell commands.

The vulnerability can be exploited by sending a POST request to the vulnerable endpoint with crafted command injection payloads in the cmdinput parameter. Payloads typically involve using shell metacharacters to chain additional commands after the intended command, allowing execution of arbitrary system commands. For detailed technical information and proof-of-concept examples, refer to the GitHub PoC Repository.

Detection Methods for CVE-2024-41468

Indicators of Compromise

• Unusual HTTP POST requests to /goform/exeCommand endpoint from external or unexpected IP addresses
• Web server logs showing cmdinput parameters containing shell metacharacters (;, |, `, $())
• Unexpected outbound connections from the router to external command-and-control infrastructure
• Modified router configuration files or unauthorized user accounts created on the device

Detection Strategies

• Implement network intrusion detection rules to identify HTTP requests targeting /goform/exeCommand with suspicious payloads
• Monitor for command injection patterns in web application firewall (WAF) logs targeting the router's management interface
• Deploy network traffic analysis to detect anomalous outbound connections from IoT devices on the network
• Review router access logs for unauthorized access attempts or unusual parameter values

Monitoring Recommendations

• Isolate IoT devices and routers on dedicated network segments with strict firewall rules
• Enable logging on upstream network devices to capture traffic to and from the Tenda FH1201
• Implement alerting for any external access attempts to router management interfaces
• Conduct periodic vulnerability scanning of network infrastructure devices

How to Mitigate CVE-2024-41468

Immediate Actions Required

• Restrict access to the router's web management interface to trusted internal networks only
• Implement firewall rules to block external access to port 80/443 on the Tenda FH1201 device
• Consider network segmentation to isolate the affected router from critical network assets
• Monitor for and investigate any suspicious activity on the network until remediation is complete

Patch Information

At the time of publication, no official patch from Tenda has been identified for this vulnerability. Organizations should contact Tenda directly for firmware update availability and monitor the vendor's support channels for security updates. Given the lack of vendor remediation resources, consider replacing affected devices with actively maintained alternatives that receive regular security updates.

Workarounds

• Disable remote management features if not required for operational purposes
• Restrict management interface access to specific trusted IP addresses using access control lists
• Place the router behind a properly configured firewall that blocks access to the management interface from untrusted networks
• Consider deploying a VPN solution for secure remote administration instead of direct web interface exposure

# Example iptables rules to restrict management interface access
# Block external access to router management port
iptables -A INPUT -p tcp --dport 80 -s ! 192.168.1.0/24 -j DROP
iptables -A INPUT -p tcp --dport 443 -s ! 192.168.1.0/24 -j DROP

# Allow management access only from specific admin workstation
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.100 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 192.168.1.100 -j ACCEPT