Comcast Xfinity Security System Helps Burglars Break into Homes

• By Sydny Shepard
• Jan 05, 2016

Our new digital age gives us the benefit of being able to check up on our homes while we are away. The newest and most popular security systems are able to send texts and digital notifications right to your phone so that you can be aware of problems while you are away. Pretty great, isn’t it? But what if your system isn’t protecting your home, instead sending false reports while someone is in your home?

Security researchers at Rapid7 have found vulnerabilities in Comcast’s Xfinity Home Security system that would cause it to falsely report that a property’s windows and doors are closed and secure even if they have been opened. It could also fail to sense an intruder’s motion.

The system uses a ZigBee-based protocol to communicate and operate over the 2.4 GHz radio frequency band. All a thief has to do is use radio jamming equipment to block the signals that pass from a door, window, or motion sensor to the home’s baseband hub. Instead of signaling that something is wrong, the system will send a false positive and continue to report that everything inside the house is intact and safe.

Once the signals are open again, it can take the sensors anywhere from a few minutes to three hours to re-establish communication with the hub. And once they do, the base station hub, which has a digital readout, provides no indication that conditions changed during that period.

Once the sensor for a door or window comes back online, there is no way to let the base station know that something was tampered with because no signals were being received at the time.

It makes sense that the home base would ignore small communication breaks, because you wouldn’t want to be alerted every time you turn on the microwave, but this kind of device could take hours to come back online, limiting the amount of security you are paying for.

The most problematic thing is that Comcast gives home security systems a sign to put in their front yard that signifies that the home uses the service. This gives anyone who knows how to jam the signal a path to the most vulnerable homes.

While homeowners aren’t able to take any practical movements to mitigate their risk of an attack, the vendor could easily fix the problem with a firmware patch that would instruct the system to send alerts when something is not okay with it.

It is unclear, whether Comcast plans to issue a patch. Rapid7 has tried several times to contact the company, but has not received any communication back.