CVE-2026-2530 Overview
A command injection vulnerability has been identified in Wavlink WL-WN579A3 routers running firmware versions up to 20210219. This vulnerability affects the AddMac function within the /cgi-bin/wireless.cgi file, where improper handling of the macAddr argument allows attackers to inject and execute arbitrary system commands. The attack can be carried out remotely by authenticated users, potentially enabling complete device compromise.
Critical Impact
Remote command injection allows attackers to execute arbitrary commands on vulnerable Wavlink routers, potentially leading to full device takeover, network reconnaissance, and lateral movement within compromised networks.
Affected Products
- Wavlink WL-WN579A3 Firmware (up to version 20210219)
- Wavlink WL-WN579A3 Hardware
Discovery Timeline
- 2026-02-16 - CVE-2026-2530 published to NVD
- 2026-02-18 - Last updated in NVD database
Technical Details for CVE-2026-2530
Vulnerability Analysis
This command injection vulnerability (CWE-77) exists in the AddMac function of the Wavlink WL-WN579A3 router's web management interface. The vulnerability is classified under both CWE-74 (Improper Neutralization of Special Elements in Output Used by a Downstream Component) and CWE-77 (Improper Neutralization of Special Elements used in a Command).
The flaw occurs when user-supplied input through the macAddr parameter is passed directly to a system command without proper sanitization or validation. This allows an authenticated attacker to append arbitrary shell commands that will be executed with the privileges of the web server process, typically root on embedded devices.
Root Cause
The root cause stems from insufficient input validation in the AddMac function located at /cgi-bin/wireless.cgi. The macAddr parameter accepts user input that is subsequently incorporated into system command execution without proper sanitization. The lack of input filtering for shell metacharacters (such as ;, |, &, and backticks) allows command chaining and injection attacks.
Attack Vector
The attack vector is network-based, requiring the attacker to have authenticated access to the device's web management interface. Once authenticated, an attacker can craft a malicious HTTP request containing shell commands within the macAddr parameter. These commands are then executed by the underlying operating system.
The vulnerability allows attackers to:
- Execute arbitrary system commands with elevated privileges
- Modify router configuration
- Establish persistent backdoor access
- Pivot to other devices on the network
- Intercept or manipulate network traffic
Technical details and proof-of-concept information are available in the GitHub IoT Vulnerability Document.
Detection Methods for CVE-2026-2530
Indicators of Compromise
- Unusual HTTP requests to /cgi-bin/wireless.cgi containing shell metacharacters in the macAddr parameter
- Unexpected outbound network connections from the router
- Modified router configurations or unauthorized user accounts
- Presence of unfamiliar processes or services running on the device
- Suspicious entries in system logs indicating command execution attempts
Detection Strategies
- Monitor web server access logs for requests containing shell metacharacters (;, |, &, backticks) in POST/GET parameters
- Implement intrusion detection rules to flag anomalous HTTP requests targeting /cgi-bin/wireless.cgi
- Deploy network traffic analysis to identify command-and-control communications originating from IoT devices
- Utilize SentinelOne Singularity to detect post-exploitation behavior and lateral movement attempts
Monitoring Recommendations
- Enable verbose logging on network perimeter devices to capture requests to IoT management interfaces
- Implement network segmentation to isolate IoT devices and monitor cross-segment traffic
- Configure alerts for unusual process execution patterns on embedded devices
- Regularly audit device configurations for unauthorized modifications
How to Mitigate CVE-2026-2530
Immediate Actions Required
- Restrict access to the router's web management interface to trusted internal networks only
- Implement strong authentication credentials and disable default accounts
- Place affected devices behind a properly configured firewall
- Monitor network traffic for exploitation attempts
- Consider replacing vulnerable devices if no patch is available
Patch Information
The vendor (Wavlink) was contacted about this vulnerability but did not respond. As of the last update on 2026-02-18, no official patch has been released. Organizations using affected devices should implement compensating controls and consider device replacement with supported alternatives.
Additional technical information can be found at VulDB #346118.
Workarounds
- Disable remote management access to the device's web interface
- Implement network-level access controls (firewall rules, VLANs) to restrict management access
- Deploy a web application firewall (WAF) to filter malicious requests targeting the CGI interface
- Consider using a VPN for remote administration instead of exposing the management interface directly
- Monitor for vendor updates and apply patches when they become available
# Example: Restrict management interface access using iptables on upstream firewall
# Block external access to router management port (typically 80/443)
iptables -A FORWARD -d <ROUTER_IP> -p tcp --dport 80 -j DROP
iptables -A FORWARD -d <ROUTER_IP> -p tcp --dport 443 -j DROP
# Allow only trusted admin subnet
iptables -I FORWARD -s <ADMIN_SUBNET>/24 -d <ROUTER_IP> -p tcp --dport 80 -j ACCEPT
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
