People love to criticize Tesla Motors Inc (TSLA) for its cars being vulnerable to hacking, but the Model S isn’t the only one. Last summer a couple of hackers were able to compromise a Toyota Prius and a Ford Escape. Now one auto expert tells ValueWalk that Toyota Motor Corp (ADR) (NYSE:TM) (TYO:7203)’s and Ford Motor Company (NYSE:F)’s cars are considered to be among the most easily hackable.

Toyota, Ford cars hacked

Videos like this one originally posted by Forbes last year show just how dangerous it can be if a vehicle is hacked.

Of course does the average person have to worry about their car being hacked? Probably not, at least for now. But a hacking attack earlier this year involving smart fridges and other connected appliances highlights that this is a concern automakers should take seriously before cars become any more connected than they already are.

Virtually any car can be hacked

Tesla Hack

Automotive expert Jordan Perch of DMV.com told ValueWalk that right now, almost every car is vulnerable to hacking—not just Tesla Motors Inc (NASDAQ:TSLA)’s Model S sedan. And what all hackers can do to cars may surprise you. It goes far beyond the recent vulnerability uncovered with Tesla’s car, which mostly involves unlocking the doors.

“They can apply a car’s brakes without even entering the car, using only a laptop, instead,” Perch said. “They can mess with the GPS system, giving the driver wrong directions, and they can also change the numbers on the car’s speedometer. A car’s steering can be hacked, as well, through a self-parking system, which can be found in many new cars nowadays.”

Needless to say, if someone messes with the steering or brakes on a car while it is traveling at high speeds, the result can be extremely dangerous, if not deadly. Hackers can also intercept the signal from a key fob, making it possible for them to gain access to a car—just like they can with Tesla Motors Inc (NASDAQ:TSLA)’s Model S.

Toyota, Ford, GM vehicles are vulnerable too

And while Tesla Motors Inc (NASDAQ:TSLA) is the one which has gotten the flak for the vulnerabilities in its software, Perch tells ValueWalk that that Toyota Motor Corp (ADR) (NYSE:TM) (TYO:7203)’s Safety Connect System and Ford Motor Company (NYSE:F)’s SYNC system are believed to be the most vulnerable to hacking. However, there have been no reported cases of these companies’ cars actually being hacked, other than the demonstration of the hack on the Ford Escape last year. Perch also says General Motors Company (NYSE:GM) may have a vulnerability to be concerned with as well.

“General Motors’ OnStar system is thought to be vulnerable to wireless hacking attacks, as well,” Perch told ValueWalk. “You can access the car’s cellular network and send a malicious file, such as an MP3 file, which will allow you to take control of the car’s on-board computer.”

How hackers can break in

Perch highlighted a number of different methods hackers could use if they wanted to gain control of a car. Some require the hacker to be within 900 feet of the car, while others can be done from further away. One area of vulnerability includes cars’ infotainment system, which has cellular radio and Bluetooth technology. According to Perch, hackers can connect to a car’s internal network using a smartphone or laptop through these technologies.

Hackers can also install a virus or computer worm into a car’s wireless connection or diagnostics system. In other words, those convenient systems allowing for over-the-air updates for Tesla Motors Inc (NASDAQ:TSLA)’s cars and others also offer a vulnerability if automakers do not take steps to protect them from digital intruders.

Hackers can also gain access through a very unexpected place: the car’s tire pressure monitoring system. Perch says there have been some reports that Tesla Motors Inc (NASDAQ:TSLA)’s Model S has been hacked through its tire pressure sensors. That hack enables the intruder to remotely unlock the doors of the car—just by connecting to the wireless protocol for the tire pressure monitoring system. Other areas of vulnerability include dedicated short-range communication systems and other remote keyless entry systems. However, all of these hacks can only be done within 900 feet of the car.

How adding Wi-Fi could make hacking easier

Tesla Motors Inc (NASDAQ:TSLA) recently made a deal to add wireless broadband access from AT&T Inc. (NYSE:T) to its vehicles, and it isn’t the only one to plan the addition of wireless connectivity. General Motors Company (NYSE:GM) also said it will bring 4G LTE mobile Internet to its vehicles next year. The goal of these initiatives is to basically turn cars into smartphones which actually drive down the road.

A recent study regarding the use of the browser on Tesla Motors Inc (NASDAQ:TSLA)’s massive touchscreens found out just how popular connectivity is in cars. But where there’s connectivity, there’s the potential for anyone to gain access to a vehicle through its computer. There’s been talk that General Motors Company (NYSE:GM) could offer up its in-car Internet in such a way as to create a 4G LTE hot spot. According to Perch, adding 4G LTE to cars not only makes them smarter, but also potentially more vulnerable.

“As GM embeds 4G LTE connectivity in its cars, making them WiFi hotspots, they become extremely exposed to outside attacks, even though their internal networks are encrypted,” Perch said. If you have a vehicle that is equipped with OnStar 4G LTE, you can connect your smartphone, laptop, or tablet to high-speed Internet, but this also means that hackers can break into the car’s internal network remotely, without physically connecting their devices to the car’s dashboard.”

Tesla takes steps to protect against hacking

Tesla motors

Tesla Motors Inc (NASDAQ:TSLA) has already taken steps to protect its cars against hacking. Last year a former Dell executive highlighted another vulnerability in the Model S’s computer system. After that, Tesla hired the so-called “hacker princess,” Kristin Paget, who was with Apple Inc. (NASDAQ:AAPL) previously.

At this point there are no details from Tesla Motors Inc (NASDAQ:TSLA) regarding exactly what steps it is taking to protect against hackers. However, as concerns about this issue increase, it would make sense that the automaker, which is leading the way in technology currently, would also lead the way in providing protection from hackers for drivers of its cars. And with Paget on Tesla’s side, the automaker has a good chance at beefing up security very quickly.