CVE-2024-38944: Intelight X-1L Traffic Controller RCE Flaw

CVE-2024-38944 Overview

CVE-2024-38944 is a critical remote code execution vulnerability affecting the Intelight X-1L Traffic Controller running Maxtime firmware version 1.9.6. The vulnerability exists in the /cgi-bin/generateForm.cgi component and can be exploited by a remote attacker to execute arbitrary code on vulnerable traffic controller devices without authentication.

Critical Impact

Remote attackers can execute arbitrary code on critical infrastructure traffic controllers, potentially disrupting traffic management systems and public safety operations.

Affected Products

• Intelight X-1L Traffic Controller
• Maxtime Firmware version 1.9.6

Discovery Timeline

• 2024-07-22 - CVE-2024-38944 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2024-38944

Vulnerability Analysis

This vulnerability is classified as CWE-94 (Improper Control of Generation of Code - Code Injection). The affected component /cgi-bin/generateForm.cgi?formID=142 fails to properly sanitize user-supplied input before processing, allowing attackers to inject and execute arbitrary code on the underlying system.

Traffic controllers like the Intelight X-1L are critical infrastructure devices used to manage traffic signals at intersections. The network-accessible nature of this vulnerability, combined with the lack of authentication requirements, makes it particularly dangerous in scenarios where these devices may be exposed to untrusted networks.

The vulnerability requires no user interaction and can be exploited from the network with low attack complexity, presenting a severe risk to organizations deploying these traffic controllers in production environments.

Root Cause

The root cause of this vulnerability lies in improper input validation within the CGI component. The generateForm.cgi script fails to adequately sanitize the formID parameter and potentially other inputs, allowing an attacker to inject malicious code that is subsequently executed by the server. This is a classic code injection vulnerability where untrusted input is processed without proper validation or encoding.

Attack Vector

The attack vector is network-based, meaning an attacker with network access to the vulnerable device can exploit this vulnerability remotely. The exploitation path involves crafting malicious HTTP requests to the /cgi-bin/generateForm.cgi endpoint with the formID=142 parameter. Due to the lack of authentication requirements and the low complexity of the attack, threat actors can easily weaponize this vulnerability.

A proof-of-concept exploit is publicly documented in a GitHub Gist by LemonSec, which provides technical details on how the vulnerability can be triggered. Organizations should review this reference to understand the exploitation mechanics and assess their exposure.

Detection Methods for CVE-2024-38944

Indicators of Compromise

• HTTP requests containing unusual payloads targeting /cgi-bin/generateForm.cgi?formID=142
• Unexpected processes spawned by CGI handlers on traffic controller devices
• Anomalous outbound network connections from traffic controller systems
• Unauthorized configuration changes or file modifications on affected devices

Detection Strategies

• Monitor web server logs for requests to /cgi-bin/generateForm.cgi with suspicious query parameters
• Implement network intrusion detection rules to identify exploitation attempts against this endpoint
• Deploy endpoint detection and response (EDR) solutions capable of monitoring CGI process behavior
• Establish baseline behavior for traffic controllers and alert on deviations

Monitoring Recommendations

• Enable comprehensive logging on all traffic controller devices and forward logs to a centralized SIEM
• Monitor for command execution patterns indicative of code injection attacks
• Implement network segmentation monitoring to detect lateral movement from compromised traffic infrastructure
• Regularly audit access logs for the affected CGI endpoints

How to Mitigate CVE-2024-38944

Immediate Actions Required

• Isolate affected Intelight X-1L Traffic Controllers from public network access immediately
• Implement network segmentation to restrict access to traffic controller management interfaces
• Deploy web application firewall (WAF) rules to filter malicious requests to the vulnerable CGI endpoint
• Conduct an inventory assessment to identify all deployed Intelight X-1L devices running firmware version 1.9.6

Patch Information

At the time of this writing, no vendor patch information is publicly available for this vulnerability. Organizations should contact Intelight directly to inquire about firmware updates that address CVE-2024-38944. Given the critical nature of this vulnerability and its impact on public infrastructure, prioritizing vendor communication is essential.

Workarounds

• Restrict network access to traffic controller management interfaces using firewall rules
• Implement VPN requirements for remote administrative access to traffic controllers
• Deploy reverse proxy configurations to filter requests to vulnerable CGI endpoints
• Enable IP allowlisting to permit access only from authorized management stations

# Example firewall rule to restrict access to traffic controller management interface
# Adjust IP ranges according to your network architecture
iptables -A INPUT -p tcp --dport 80 -s 10.0.0.0/8 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP