CVE-2024-1781: Totolink X6000r Firmware RCE Vulnerability

CVE-2024-1781 Overview

A critical command injection vulnerability has been identified in the Totolink X6000R AX3000 WiFi 6 router running firmware version 9.4.0cu.852_20230719. This vulnerability exists in the setWizardCfg function within the /cgi-bin/cstecgi.cgi component of the shttpd web server. Successful exploitation allows unauthenticated remote attackers to execute arbitrary system commands on the affected device, potentially leading to complete device compromise.

Critical Impact

This network-accessible command injection vulnerability requires no authentication and can be exploited remotely, allowing attackers to gain full control of affected Totolink routers.

Affected Products

• Totolink X6000R AX3000 WiFi 6 Router
• Totolink X6000R Firmware version 9.4.0cu.852_b20230719

Discovery Timeline

• February 23, 2024 - CVE-2024-1781 published to NVD
• April 1, 2025 - Last updated in NVD database

Technical Details for CVE-2024-1781

Vulnerability Analysis

This command injection vulnerability (CWE-77) affects the web interface component of the Totolink X6000R router. The vulnerability resides in the setWizardCfg function, which is accessible through the /cgi-bin/cstecgi.cgi endpoint served by the shttpd web server. When processing user-supplied input, the function fails to properly sanitize parameters before passing them to system shell commands, creating an opportunity for attackers to inject and execute arbitrary commands on the underlying operating system.

The vulnerability is particularly severe because it can be exploited over the network without requiring any authentication credentials. An attacker with network access to the router's management interface can craft malicious requests that inject shell commands into the vulnerable function, achieving remote code execution with the privileges of the web server process.

Root Cause

The root cause of this vulnerability is improper input validation in the setWizardCfg function. User-controlled input is not adequately sanitized or escaped before being incorporated into system command strings. This allows specially crafted input containing shell metacharacters and command sequences to break out of the intended command context and execute attacker-controlled commands.

Attack Vector

The attack vector for CVE-2024-1781 is network-based, requiring the attacker to have access to the router's web management interface. The attack can be executed remotely without authentication by sending specially crafted HTTP requests to the /cgi-bin/cstecgi.cgi endpoint, targeting the vulnerable setWizardCfg function.

The exploitation mechanism involves sending malicious parameters containing shell command injection sequences. When the router processes these requests, the injected commands are executed in the context of the web server, typically with elevated privileges sufficient to compromise the entire device.

Additional technical details regarding the exploitation of this vulnerability can be found in the GitHub RCE Exploit Reference and the VulDB advisory.

Detection Methods for CVE-2024-1781

Indicators of Compromise

• Unexpected HTTP POST requests to /cgi-bin/cstecgi.cgi containing shell metacharacters such as ;, |, &, or backticks
• Unusual outbound network connections originating from the router's management IP address
• Presence of unauthorized files or scripts in the router's filesystem
• Unexpected processes running on the device that are not part of normal router operations

Detection Strategies

• Monitor web server logs for requests to /cgi-bin/cstecgi.cgi containing command injection patterns or suspicious payloads
• Deploy network intrusion detection signatures to identify command injection attempts targeting Totolink routers
• Implement network segmentation to isolate IoT devices and monitor traffic anomalies from router management interfaces
• Configure alerts for any administrative access attempts from untrusted network segments

Monitoring Recommendations

• Enable comprehensive logging on network perimeter devices to capture traffic to and from Totolink router management interfaces
• Implement behavioral monitoring to detect unusual command execution patterns on embedded devices
• Regularly audit router configurations for unauthorized changes or the addition of persistent backdoors

How to Mitigate CVE-2024-1781

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 affected router
• Consider temporarily disabling the web management interface if not required for operations
• Monitor for and investigate any suspicious network activity involving affected devices

Patch Information

At the time of disclosure, the vendor (Totolink) was contacted but did not respond. Users should check the Totolink support website for any firmware updates that may address this vulnerability. Until a patch is available, implementing the recommended mitigations is critical.

Workarounds

• Disable remote management access to the router's web interface entirely
• Place the router behind an additional firewall that restricts access to the management interface
• Use VPN access for any required remote administration instead of exposing the web interface directly
• Consider replacing the affected device with a router from a vendor with a more responsive security disclosure process

# Example firewall rule to restrict access to router management interface
# Block external access to router management ports
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