CVE-2026-1687: Tenda HG10 Router RCE Vulnerability

CVE-2026-1687 Overview

A command injection vulnerability has been identified in the Tenda HG10 router running firmware version US_HG7_HG9_HG10re_300001138_en_xpon. The vulnerability exists within the Boa Webserver component, specifically in the /boaform/formSamba endpoint. By manipulating the serverString argument, an unauthenticated remote attacker can inject and execute arbitrary operating system commands on the affected device.

Critical Impact

Remote attackers can achieve command execution on vulnerable Tenda HG10 routers without authentication, potentially leading to full device compromise, network pivoting, or integration into botnet infrastructure.

Affected Products

• Tenda HG10 with firmware US_HG7_HG9_HG10re_300001138_en_xpon
• Tenda HG7 (potentially affected based on shared firmware)
• Tenda HG9 (potentially affected based on shared firmware)

Discovery Timeline

• 2026-01-30 - CVE-2026-1687 published to NVD
• 2026-02-04 - Last updated in NVD database

Technical Details for CVE-2026-1687

Vulnerability Analysis

This command injection vulnerability (CWE-74) affects the Boa Webserver running on Tenda HG10 devices. The vulnerability resides in the /boaform/formSamba endpoint, which processes HTTP requests related to Samba file sharing configuration. The serverString parameter is passed to a system command without proper sanitization or validation, allowing attackers to inject arbitrary shell commands.

The attack can be executed remotely over the network without requiring authentication, making it particularly dangerous for internet-exposed devices. An exploit has been made publicly available, which significantly increases the risk of active exploitation in the wild.

Root Cause

The root cause is improper input validation (CWE-74 - Injection) in the handling of the serverString parameter within the Boa Webserver's Samba configuration form handler. User-supplied input is concatenated directly into a command string that is executed by the underlying operating system shell without proper sanitization, escaping, or parameterization.

Attack Vector

The attack vector is network-based, requiring no user interaction or prior authentication. An attacker can craft a malicious HTTP request to the /boaform/formSamba endpoint with a specially crafted serverString parameter containing shell metacharacters and commands.

The vulnerability can be exploited by sending a crafted HTTP POST request to the vulnerable endpoint. The serverString parameter accepts user input that is passed directly to a system shell without sanitization. Attackers can inject command separators (such as semicolons, pipes, or backticks) followed by arbitrary commands. For detailed exploitation examples, refer to the GitHub PoC Documentation.

Detection Methods for CVE-2026-1687

Indicators of Compromise

• Unusual HTTP POST requests to /boaform/formSamba endpoint containing shell metacharacters (;, |, $(), backticks) in the serverString parameter
• Unexpected outbound connections from router devices to external IP addresses
• Unauthorized processes spawning from the Boa Webserver process
• Modifications to router configuration files or firmware

Detection Strategies

• Deploy web application firewall rules to detect and block command injection patterns in HTTP requests to /boaform/ endpoints
• Monitor network traffic for anomalous HTTP POST requests targeting Tenda router administration interfaces
• Implement intrusion detection signatures for known Tenda HG10 exploitation patterns

Monitoring Recommendations

• Enable logging on network perimeter devices to capture traffic to/from Tenda router management interfaces
• Monitor for unexpected DNS queries or outbound connections originating from IoT network segments
• Implement network segmentation to isolate IoT devices and enable easier traffic monitoring

How to Mitigate CVE-2026-1687

Immediate Actions Required

• Restrict network access to the router's web administration interface to trusted management networks only
• Disable remote management features if not required for operations
• Place affected devices behind a firewall that blocks external access to port 80/443
• Monitor Tenda's official channels for firmware updates addressing this vulnerability

Patch Information

At the time of publication, no official patch has been released by Tenda. Organizations should monitor the Tenda Official Website for security advisories and firmware updates. Consider replacing affected devices with alternatives from vendors with better security update practices if patches are not released in a timely manner.

Workarounds

• Implement network-level access controls to restrict access to the router's management interface to internal trusted IPs only
• Deploy a web application firewall (WAF) in front of the device to filter malicious requests containing command injection payloads
• Disable the Samba functionality if not required, which may remove the vulnerable endpoint from the attack surface
• Segment IoT devices on a separate VLAN with strict egress filtering

# Example iptables rules to restrict access to router management interface
# Apply these rules on an upstream firewall or the router if supported

# Allow management access only from trusted admin network
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP