CVE-2024-41992: Wi-Fi Test Suite RCE Vulnerability

CVE-2024-41992 Overview

CVE-2024-41992 is a critical OS command injection vulnerability affecting the Wi-Fi Alliance wfa_dut component within the Wi-Fi Test Suite through version 9.0.0. The vulnerability arises from improper input sanitization when processing 802.11x frames, where the unsafe system() library function is used to execute commands. This allows attackers to inject and execute arbitrary OS commands on vulnerable devices.

On Arcadyan FMIMG51AX000J devices, this vulnerability enables remote code execution as root via traffic to TCP port 8000 or 8080 on a LAN interface through the wfaTGSendPing function. On other affected devices, exploitation may be possible over a WAN interface, significantly expanding the attack surface.

Critical Impact

Remote code execution as root on vulnerable Wi-Fi devices through command injection in 802.11x frame processing, potentially allowing complete device compromise.

Affected Products

• Wi-Fi Alliance Wi-Fi Test Suite through version 9.0.0
• Arcadyan FMIMG51AX000J devices with wfa_dut component
• Other devices implementing Wi-Fi Test Suite with exposed management interfaces

Discovery Timeline

• 2024-11-11 - CVE CVE-2024-41992 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2024-41992

Vulnerability Analysis

This vulnerability is classified as CWE-78 (Improper Neutralization of Special Elements used in an OS Command), commonly known as OS command injection. The root issue lies in the wfa_dut daemon's handling of network input when processing 802.11x frames for Wi-Fi testing purposes.

The wfaTGSendPing function accepts user-controlled input and passes it to the system() library function without proper sanitization. This architectural flaw allows attackers to inject shell metacharacters and arbitrary commands that execute with the privileges of the wfa_dut process—typically root on embedded devices.

The adjacent network attack vector requires the attacker to be on the same network segment, but the lack of authentication requirements and user interaction makes exploitation straightforward once network access is obtained.

Root Cause

The vulnerability stems from the use of the inherently unsafe system() function to execute ping commands. The wfa_dut component takes user-supplied input from 802.11x frames and incorporates it directly into shell commands without proper input validation or sanitization. This allows shell metacharacters such as semicolons, pipes, and backticks to break out of the intended command context and execute arbitrary commands.

The Wi-Fi Test Suite is designed for testing and certification purposes, which may explain the permissive input handling. However, when this software remains deployed on production devices with network-accessible interfaces, it creates a severe security risk.

Attack Vector

Exploitation occurs via network traffic directed at TCP ports 8000 or 8080, which host the wfa_dut service. An attacker on an adjacent network can craft malicious 802.11x frames containing shell commands embedded within parameters processed by wfaTGSendPing. When the vulnerable function passes this input to system(), the injected commands execute with root privileges.

The attack flow involves:

1. Identifying devices with wfa_dut listening on TCP port 8000 or 8080
2. Crafting malicious frames with command injection payloads
3. Sending the crafted traffic to the target device
4. Achieving command execution as root

For detailed technical analysis and proof-of-concept information, refer to the SSD Disclosure Advisory and CERT Vulnerability Report #123336.

Detection Methods for CVE-2024-41992

Indicators of Compromise

• Unexpected network connections to TCP ports 8000 or 8080 on internal devices
• Anomalous process spawning from the wfa_dut process or its parent
• Unusual command execution patterns in system logs, particularly commands containing shell metacharacters
• New or modified files in system directories created by root-owned processes

Detection Strategies

• Monitor network traffic for connections to TCP ports 8000 and 8080 on embedded devices and routers
• Implement intrusion detection signatures to identify malformed 802.11x frames with shell metacharacter patterns
• Deploy endpoint monitoring to detect child processes spawned by wfa_dut that deviate from expected ping operations
• Enable command-line auditing on Linux-based embedded devices to capture suspicious shell activity

Monitoring Recommendations

• Configure network monitoring to alert on traffic to TCP ports 8000/8080 from unexpected sources
• Review embedded device logs for evidence of command execution attempts containing injection characters
• Establish baseline behavior for wfa_dut processes and alert on deviations
• Monitor for new outbound connections from embedded devices that may indicate post-exploitation activity

How to Mitigate CVE-2024-41992

Immediate Actions Required

• Identify all devices in your environment running Wi-Fi Test Suite or wfa_dut components
• Disable or remove the wfa_dut service from production devices where Wi-Fi testing functionality is not required
• Block incoming traffic to TCP ports 8000 and 8080 on affected devices at the network perimeter and via host-based firewalls
• Segment affected devices from critical network resources until remediation is complete

Patch Information

Consult your device vendor for firmware updates that address CVE-2024-41992. The Wi-Fi Alliance Wi-Fi Test Suite is intended for certification testing environments and should not be deployed on production devices. If the software must be used, ensure it is only accessible from isolated testing networks.

For additional guidance, refer to the CERT Vulnerability Report #123336.

Workarounds

• Disable the wfa_dut service entirely on production devices using systemctl disable wfa_dut or equivalent
• Apply firewall rules to block all traffic to TCP ports 8000 and 8080 on affected devices
• Physically or logically isolate devices requiring Wi-Fi Test Suite functionality from production networks
• If disabling is not possible, restrict access to management ports using ACLs limited to trusted testing systems

# Configuration example
# Block access to wfa_dut ports using iptables
iptables -A INPUT -p tcp --dport 8000 -j DROP
iptables -A INPUT -p tcp --dport 8080 -j DROP

# Disable the wfa_dut service (if systemd is available)
systemctl stop wfa_dut
systemctl disable wfa_dut