CVE-2020-12126

Vulnerability

The WAVLINK WN530H4 wireless router running firmware version M30H4.V5030.190403 contains multiple authentication bypass vulnerabilities in the /cgi-bin/ endpoint. An attacker can access sensitive router settings and configuration variables without any authentication, as the endpoint fails to enforce access controls. The affected product is the WL-WN530H4 AC1200 High Power Dual Band Wireless Router [1].

Exploitation

An attacker with network access to the router's management interface can send HTTP requests to the /cgi-bin/ endpoint without requiring any prior authentication. The lack of access control allows unauthenticated users to interact with various CGI scripts exposed on that endpoint. No special privileges, user interaction, or race conditions are needed; simply sending crafted requests to the vulnerable endpoint is sufficient.

Impact

Successful exploitation allows an unauthenticated attacker to leak router settings (information disclosure), change configuration variables (data integrity compromise), and cause denial of service by disrupting normal router operations. The attacker gains unauthorized access to the router's internals without requiring any credentials.

Mitigation

As of the publication date (2020-10-02), no official patch or firmware update has been released to address these vulnerabilities. Users are advised to restrict network access to the router's management interface, such as by not exposing it to the internet and using strong firewall rules. The manufacturer's product page [1] does not mention any fix. The vulnerability is not listed in CISA's Known Exploited Vulnerabilities (KEV) catalog.