CVE-2026-110957 in WL-WN530BE2-A
Summary
by MITRE • 10/15/2026
A vulnerability has been found in Wavlink WL-WN530BE2-A up to M30BE2_V250604. The affected element is the function sub_12580 of the file api.cgi of the component Login Processing. The manipulation of the argument REMOTE_ADDR leads to os command injection. It is possible to initiate the attack remotely. The exploit has been disclosed to the public and may be used. Upgrading to version 2026-09-24-841a51c6d5_tclinux.bin is sufficient to fix this issue. You should upgrade the affected component. The vendor confirms: "We confirm the finding, and it has already been addressed. In the current firmware the api=info&client=app handler no longer builds a shell command: the login script is now invoked through an argument vector (execvp) instead of system(), and the client address is length-limited and null-checked."
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Analysis
by VulDB Data Team • 10/15/2026
The Wavlink WL-WN530BE2-A wireless router, specifically firmware versions up to M30BE2_V250604, contains a critical remote code execution vulnerability within its web management interface. This flaw resides in the Login Processing component, specifically affecting the api.cgi file and the sub_12580 function responsible for handling authentication requests. The core technical issue is an operating system command injection vulnerability triggered by improper validation of input data derived from the REMOTE_ADDR environment variable. In many embedded web server implementations, this variable reflects the IP address of the client making the request. When this value is passed directly to a shell execution context without adequate sanitization or length constraints, it allows attackers to inject arbitrary operating system commands into the router's underlying Linux kernel environment.
This vulnerability aligns with CWE-78, which describes Improper Neutralization of Special Elements used in an OS Command, commonly known as OS Command Injection. The attack vector is classified under MITRE ATT&CK technique T1059, specifically command and scripting interpretation via the operating system shell. Because the vulnerable function processes HTTP requests remotely over the network, any unauthenticated attacker with access to the router's management interface can exploit this flaw. By manipulating the REMOTE_ADDR header or parameter during an authentication attempt, a malicious actor can execute arbitrary commands with the privileges of the web server process, which often runs as root in embedded devices due to legacy design choices and lack of privilege separation.
The operational impact of this vulnerability is severe, potentially leading to complete compromise of the device. An attacker could use this access to exfiltrate sensitive network configuration data, including Wi-Fi passwords and ISP credentials stored on the router. Furthermore, the compromised device can be turned into a node within a botnet, used for launching distributed denial-of-service attacks against other targets, or serve as an entry point to pivot deeper into the local area network where it may expose more vulnerable IoT devices or workstations. The persistence of such access allows attackers to maintain long-term control over the infrastructure, potentially modifying DNS settings to redirect traffic through malicious servers for phishing or man-in-the-middle attacks.
Vendor confirmation indicates that this issue has been acknowledged and addressed in newer firmware releases. The remediation strategy involves upgrading the device to version 2026-09-24-841a51c6d5_tclinux.bin or later. The technical fix implemented by the vendor addresses the root cause of the injection flaw through multiple defensive layers. First, the login script invocation mechanism was refactored from using system() to execvp(). This change is critical because system() invokes a shell interpreter (typically /bin/sh) which processes special characters and command separators, whereas execvp() executes the binary directly without invoking an intermediate shell, thereby neutralizing most injection payloads. Second, the vendor implemented strict input validation by length-limiting the client address field and adding null-byte checks. These measures prevent buffer overflow conditions and ensure that unexpected data structures do not corrupt memory or alter execution flow.
Organizations managing fleets of these routers should prioritize immediate patching to mitigate the risk of exploitation. Since public exploits for this vulnerability exist, automated scanning tools are likely already targeting vulnerable devices on the internet. In addition to applying the firmware update, administrators should ensure that remote management interfaces are disabled if not strictly necessary, and that strong, unique passwords are enforced for local access. Regular monitoring of vendor security advisories is recommended to stay informed about future patches and emerging threats affecting embedded networking equipment.