Hundreds of millions of Broadcom-based cable modems are at risk of remote hijacking due to the presence of a vulnerability dubbed Cable Haunt, CVE-2019-19494.
The flaw resides in the hardware and software component of Broadcom chips called a spectrum analyzer that protects the cable modem from signal surges and disturbances coming via the coax cable.
“There are an estimated 200 million cable modems in Europe alone. With almost no cable modem tested
For security reasons, on most cable modems, access to the spectrum analyzer is allowed only for connections from the internal network.
The research team discovered that the Broadcom chip spectrum analyzer lacks protection against DNS rebinding attacks, uses default credentials, and its firmware contains programming bugs.
A‘DNS Rebinding’ attack allows any website to create a DNS name that they are authorized to communicate with, and then make it resolve to
This attack could allow remote attackers to take over vulnerable Broadcom-based cable modems in a stealth way.
“Cable Haunt is exploited in two steps. First, access to the vulnerable endpoint is gained through a client on the local network, such as a browser. Secondly the vulnerable endpoint is hit with a buffer overflow attack, which gives the attacker control of the modem.” the researchers explained.
The Cable Haunt vulnerability affects cable modems using
Experts pointed out that firewalls could block this attack only using very specific configuration which they suspect nearly nobody to have set up.
(SecurityAffairs – Cable Haunt, hacking)