NETGEAR Router Flaw Allows Full Admin Access by Attackers

A severe authentication bypass vulnerability (CVE-2025-4978) has been uncovered in NETGEAR’s DGND3700v2 wireless routers, enabling unauthenticated attackers to gain full administrative control over affected devices.

The flaw, rated with a critical CVSSv4 score of 9.3, stems from a hidden backdoor mechanism in the router’s firmware and impacts versions V1.1.00.15_1.00.15NA.

Security researchers warn that exploitation could lead to complete network compromise, including credential theft, malware deployment, and traffic interception.

Bypassing Authentication via Embedded Backdoor

The vulnerability resides in the router’s mini_http server, a lightweight HTTP daemon responsible for handling administrative interface requests.

Attackers can trigger the flaw by accessing the unauthenticated endpoint /BRS_top.html, which sets an internal flag start_in_blankstate to 1.

This flag disables HTTP Basic Authentication checks in the sub_404930 function, effectively bypassing login credentials.

Affected Components:

• Firmware Version: V1.1.00.15_1.00.15NA
• Vulnerable Endpoint: /BRS_top.html
• Impacted ...