A team of four Danish security researchers has disclosed this week a security flaw that impacts cable modems that use Broadcom chips.
The vulnerability, codenamed Cable Haunt, is believed to impact an estimated 200 million cable modems in Europe alone, the research team said today.
The vulnerability impacts a standard component of Broadcom chips called a spectrum analyzer. This is a hardware and software component that protects the cable modem from signal surges and disturbances coming via the coax cable. The component is often used by internet service providers (ISPs) in debugging connection quality.
On most cable modems, access to this component is limited for connections from the internal network.
The research team says the Broadcom chip spectrum analyzer lacks protection against DNS rebinding attacks, uses default credentials, and also contains a programming error in its firmware.
Researchers say that by tricking users into accessing a malicious page via their browser, they can use the browser to relay an exploit to the vulnerable component and execute commands on the device.