CVE-2026-100745 in BR-6428nC
Summary
by MITRE • 09/27/2026
A vulnerability has been found in Edimax BR-6428nC 1.16. The impacted element is an unknown function of the file /goform/formWizSurvey of the component Wireless Wizard Handler. The manipulation of the argument interface1/interface2 leads to stack-based buffer overflow. Remote exploitation of the attack is possible. The exploit has been disclosed to the public and may be used.
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Analysis
by VulDB Data Team • 09/27/2026
The Edimax BR-6428nC router, specifically version 1.16 running its Wireless Wizard Handler component, contains a critical security flaw within the /goform/formWizSurvey endpoint that allows for remote code execution via stack-based buffer overflow. This vulnerability stems from improper input validation and boundary checking when processing arguments related to interface configurations, specifically parameters labeled as interface1 or interface2. The underlying C function responsible for handling these inputs fails to verify the length of user-supplied data before copying it into a fixed-size buffer on the call stack. When an attacker provides a string that exceeds the allocated memory space, the excess data overwrites adjacent memory locations, including critical control flow information such as the return address and saved frame pointer. This corruption allows for arbitrary code execution by redirecting program execution to shellcode injected within the overflowed buffer or through other exploitation techniques like Return Oriented Programming if stack canaries are present but bypassable.
From a technical perspective, this flaw is classified under CWE-121: Stack-based Buffer Overflow, which represents one of the most dangerous classes of memory corruption vulnerabilities due to its potential for full system compromise. The vulnerability resides in the web management interface handler, meaning it does not require authentication if the router's administrative panel is accessible over the network or via local area network connections where unauthenticated access might be possible depending on default configurations. In many embedded devices like this Edimax model, legacy interfaces often lack robust security controls such as input sanitization, making them prime targets for automated scanning tools and exploit kits that are publicly available in the wild. The presence of a disclosed public exploit significantly lowers the barrier to entry for attackers, enabling even those with limited technical expertise to compromise vulnerable devices by simply sending crafted HTTP requests containing oversized interface parameters.
The operational impact of this vulnerability is severe, as successful exploitation grants an attacker arbitrary code execution privileges within the context of the web server process running on the router. This typically corresponds to root or equivalent high-level system access in embedded Linux environments common in consumer-grade routers. An adversary can leverage this access to install persistent backdoors, modify routing tables to facilitate man-in-the-middle attacks, hijack DNS traffic for phishing campaigns, or use the compromised device as part of a botnet such as Mirai. Furthermore, because routers serve as gateways between internal networks and the internet, compromising one device can expose all connected devices on the local network to further exploitation, lateral movement, and data exfiltration. The lack of memory protection mechanisms like ASLR or NX in older firmware versions exacerbates this risk by making shellcode execution more predictable and reliable for attackers.
Mitigation strategies must focus on immediate isolation and remediation given the public availability of exploits. Users should immediately disconnect affected devices from any network until a fix is applied, as remote exploitation does not require prior authentication if the web interface is exposed or accessible within the local subnet. The primary defense involves upgrading to the latest firmware version provided by Edimax that addresses this buffer overflow issue through proper input length validation and bounds checking in the Wireless Wizard Handler code. If an official patch is unavailable or delayed, network-level controls such as firewall rules should be implemented to restrict access to port 80 and 443 exclusively from trusted IP addresses, effectively blocking external attack vectors. Additionally disabling unused services like Telnet and FTP reduces the overall attack surface while waiting for firmware updates. Long-term resilience requires adopting a zero-trust architecture where administrative interfaces are never exposed directly to untrusted networks and regular vulnerability assessments are conducted on all IoT devices within the infrastructure.