CVE-2022-44187

Vulnerability

A buffer overflow vulnerability exists in the Netgear R7000P router running firmware version V1.3.0.8. The flaw is located in the handling of the wan_dns1_pri parameter, which is processed without proper bounds checking [1]. An attacker can supply an overly long value for this parameter, causing a stack-based buffer overflow. The vulnerable code path is reachable through the router's web interface configuration pages, which are typically exposed on the local network and potentially accessible from the WAN side if remote management is enabled.

Exploitation

To exploit this vulnerability, an attacker must have network access to the router's administrative web interface. The attacker sends a specially crafted HTTP request containing an oversized wan_dns1_pri value to the router's configuration endpoint [1]. No authentication is required if the attacker is on the local network and the default settings are used, but authentication may be needed if the admin password is set. Successful exploitation involves overflowing the stack buffer, overwriting control data such as the return address or function pointers.

Impact

Successful exploitation of the buffer overflow can lead to denial of service due to corruption of memory, causing the router to crash or reboot. In more severe cases, an attacker may be able to achieve arbitrary code execution in the context of the vulnerable process, potentially gaining full control over the device [1]. This could allow the attacker to alter network traffic, intercept data, or pivot to other systems on the network.

Mitigation

As of the publication date (2022-11-22), no official firmware update has been released by Netgear to address this vulnerability. Users are advised to monitor Netgear's security advisory page for updates [1]. Until a fix is available, mitigating actions include restricting access to the router's management interface by disabling remote administration and ensuring it is only reachable from trusted local networks, as well as using strong admin credentials.