January 15, 2020 By Shane Schick 2 min read

An estimated 200 million modems or more may be vulnerable to an exploit dubbed Cable Haunt, which researchers said could give attackers complete control over their victims’ devices.

First discovered and detailed in a site set up by a Denmark-based security firm called Lyrebirds, the threat involves serving JavaScript-based malware code to users who have been lured to a website or who click on malicious ads. A buffer flow vulnerability in the spectrum analyzer is then exploited via a websocket connection opened by the JavaScript. At that point, cybercriminals can use Cable Haunt to do everything from make the device part of a botnet to changing its DNS settings.

Many Modems Affected by Vulnerability

A small server that’s intended to detect connectivity problems in a modem, the spectrum analyzer is key to the vulnerability, which researchers said affects a number of different manufacturers and product models. These include cable modems from Netgear’s C6250EMR and CG3700EMR, Sagemcom’s F@st 3890 and F@st 3686, and possibly Technicolor’s TC7230, among others.

Attackers taking advantage of Cable Haunt can also do so outside the local network, researchers added, by connecting the modem through the browser via malicious JavaScript code. The code is accepted because cross-origin resource sharing, which normally prevents such activity, doesn’t protect websockets.

Since cable modems typically manage all online traffic for devices connected to a network, the vulnerability means attackers could not only gain remote access but intercept private messages, redirect traffic to other sites, monitor unencrypted data and even install completely new firmware.

Researchers have created a proof-of-concept of the threat, which manufacturers may need to check, given that the 200 million estimate is restricted to devices in Europe and the risk may be even larger on a global scale.

The only exception to those vulnerable to the threat are those using Firefox, a browser whose websocket is incompatible with that used by a spectrum analyzer.

Close Off Cable Haunt’s Access

As more vendors become aware of Cable Haunt, they’ll likely issue a patch or fix that customers can use to avoid it. In the meantime, a comprehensive security information and event management (SIEM) system can be a good way to stay alert when suspicious activity starts taking place on the network.

More from

Change Healthcare discloses $22M ransomware payment

3 min read - UnitedHealth Group CEO Andrew Witty found himself answering questions in front of Congress on May 1 regarding the Change Healthcare ransomware attack that occurred in February. During the hearing, he admitted that his organization paid the attacker's ransomware request. It has been reported that the hacker organization BlackCat, also known as ALPHV, received a payment of $22 million via Bitcoin.Even though they made the ransomware payment, Witty shared that Change Healthcare did not get its data back. This is a…

Phishing kit trends and the top 10 spoofed brands of 2023

4 min read -  The 2024 IBM X-Force Threat Intelligence Index reported that phishing was one of the top initial access vectors observed last year, accounting for 30% of incidents. To carry out their phishing campaigns, attackers often use phishing kits: a collection of tools, resources and scripts that are designed and assembled to ease deployment. Each phishing kit deployment corresponds to a single phishing attack, and a kit could be redeployed many times during a phishing campaign. IBM X-Force has analyzed thousands of…

How I got started: AI security researcher

4 min read - For the enterprise, there’s no escape from deploying AI in some form. Careers focused on AI are proliferating, but one you may not be familiar with is AI security researcher. These AI specialists are cybersecurity professionals who focus on the unique vulnerabilities and threats that arise from the use of AI and machine learning (ML) systems. Their responsibilities vary, but key roles include identifying and analyzing potential security flaws in AI models and developing and testing methods malicious actors could…

Topic updates

Get email updates and stay ahead of the latest threats to the security landscape, thought leadership and research.
Subscribe today