CVE-2026-24107: Tenda W20e Firmware RCE Vulnerability

CVE-2026-24107 Overview

A critical command injection vulnerability has been discovered in Tenda W20E V4.0br_V15.11.0.6 firmware. The vulnerability stems from a failure to validate the usbPartitionName parameter, which is directly passed to the doSystemCmd function without proper sanitization. This allows remote attackers to inject and execute arbitrary operating system commands on the affected device with no authentication required.

Critical Impact

Unauthenticated remote attackers can achieve complete system compromise by injecting malicious commands through the usbPartitionName parameter, potentially leading to full device takeover, data exfiltration, and lateral movement within the network.

Affected Products

• Tenda W20E Firmware version 15.11.0.6
• Tenda W20E Hardware version 4.0
• Tenda W20E V4.0br_V15.11.0.6

Discovery Timeline

• 2026-03-02 - CVE-2026-24107 published to NVD
• 2026-03-03 - Last updated in NVD database

Technical Details for CVE-2026-24107

Vulnerability Analysis

This vulnerability represents a classic command injection flaw (CWE-94: Improper Control of Generation of Code) in embedded router firmware. The usbPartitionName parameter is accepted from user input and passed directly to the doSystemCmd function, which executes system commands on the underlying Linux operating system. Without proper input validation or sanitization, an attacker can append shell metacharacters and arbitrary commands to the parameter value, achieving remote code execution.

The network-accessible nature of this vulnerability combined with the lack of authentication requirements makes it particularly dangerous. Attackers can exploit this flaw remotely without any user interaction, potentially compromising the router and using it as a pivot point for further attacks on the internal network.

Root Cause

The root cause of CVE-2026-24107 is the absence of input validation on the usbPartitionName parameter before it is passed to the doSystemCmd function. The firmware fails to sanitize special characters such as semicolons (;), pipes (|), backticks (`), and other shell metacharacters that enable command chaining. This allows user-controlled input to break out of the intended command context and execute arbitrary system commands with the privileges of the web server process, typically running as root on embedded devices.

Attack Vector

The attack is executed over the network without requiring authentication or user interaction. An attacker can craft a malicious HTTP request containing a specially crafted usbPartitionName parameter value. By appending shell metacharacters followed by malicious commands, the attacker can:

1. Execute arbitrary commands on the router's operating system
2. Establish a reverse shell for persistent access
3. Modify router configuration and firmware
4. Intercept or redirect network traffic
5. Use the compromised device as a launching point for attacks on internal network resources

The vulnerability exploits the router's web management interface, which is often exposed on the local network and sometimes inadvertently exposed to the internet.

Detection Methods for CVE-2026-24107

Indicators of Compromise

• Unusual outbound network connections from the router to unknown external IP addresses
• Unexpected processes or services running on the router device
• Modified system files or configuration changes not authorized by administrators
• Suspicious HTTP requests to the router's web interface containing shell metacharacters in the usbPartitionName parameter

Detection Strategies

• Monitor HTTP traffic to router management interfaces for requests containing shell metacharacters (;, |, `, $()) in parameter values
• Implement network-based intrusion detection rules to identify command injection patterns targeting Tenda devices
• Review router access logs for suspicious parameter values in USB-related endpoints
• Deploy SentinelOne Singularity for network visibility and threat detection capabilities

Monitoring Recommendations

• Enable logging on all network devices and forward logs to a centralized SIEM solution
• Set up alerts for administrative access to router interfaces from unexpected source addresses
• Monitor for firmware integrity changes on critical network infrastructure devices
• Regularly audit network device configurations for unauthorized modifications

How to Mitigate CVE-2026-24107

Immediate Actions Required

• Restrict access to the router's web management interface to trusted IP addresses only
• Disable remote management if not explicitly required for operations
• Place affected Tenda W20E devices behind a firewall with strict ingress filtering
• Monitor for any indicators of compromise on affected devices
• Consider replacing vulnerable devices with supported alternatives if no patch is available

Patch Information

Check the Tenda Security Advisory for official patch information and firmware updates. Additional technical details may be found in the GitHub CVE Report. Organizations should prioritize firmware updates as soon as they become available from the vendor.

Workarounds

• Implement network segmentation to isolate vulnerable devices from critical systems
• Use access control lists (ACLs) to restrict management interface access to specific administrator workstations
• Deploy a web application firewall (WAF) in front of the management interface to filter malicious requests
• Disable USB-related functionality on the router if not required for operations
• Consider deploying network monitoring solutions to detect exploitation attempts

# Example: Restrict management interface access via firewall rules
# Allow management access only from trusted admin subnet
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP

# Block external access to management interface
iptables -A INPUT -p tcp --dport 443 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP