Defcon 22 The US emergency response system is in urgent need of better security as it’s surprisingly easy to disable or spoof 911 calls.
In a talk at Defcon 22 two doctors (who are also hackers) and a security consultant presented research into the emergency response system and how calls via fixed line, mobile phones and VoIP are routed. There’s still considerable variation in how different states set up their 911 systems,. but all are vulnerable.
You might ask why anyone would want to hack the emergency services system, since it’s not a financially rewarding target but it’s a growing problem the team said. Some people do it for mischief, but it’s also used to disrupt businesses, could be used to divert police away from a crime in progress, and there’s also been a huge rise in swatting.
Swatting is the practice of calling the emergency services and reporting a serious crime involving firearms in the hope of getting a heavily armed SWAT (special weapons and tactics) team to a target’s house, which could result in an accidental fatality.
It has been used against security journalist Brian Krebs, but also against celebrities. A 12-year-old boy successfull got SWAT teams dispatched to the houses of actor and tech investor Ashton Kutcher and pop star Justin Bieber - and however annoying Baby is it’s not worth trying to kill him for.
When calls are made to the emergency services the telecommunications provider routs them to the local 911 team, along with as much information as possible about where the call is located. With wired systems that’s limited to what subscriber information they have on file, but some mobile calls can also include GPS and all include data on which cell tower the caller is using.
In the case of the preteen swatter, the child used a text telephone (TTY) used by the disabled, to call in the false report. These terminals are transferred to an operator, who will the call the emergency services and relay the information, thus circumventing much of the location and user information usually included in calls.
The three researchers found that spoofing this information to obscure the caller’s true location is actually quite difficult, but not impossible. It is possible to strip some identifying information from a fixed line call, doing so sends a red flag to the operator, as would spoofing a GPS location.
A bigger problem is the emergency call centers themselves. These used to be airgapped from a hospital’s administrative systems but increasingly they are merged to save on money and network maintenance and are therefore much more susceptible to a denial of service attack against the telephone or computer systems.
Physical security in such centers is also usually lax and penetration testing, both digital and physical, is seldom carried out on the calls centers and staff get almost no training on social engineering techniques.
There are some quick and cheap fixes, the team said. A unified security testing structure for networks and phones would be a big help they said, and adding an extra step in phone calls - such as asking a caller to press one for English and two for Spanish - which would stop or slow an automated attack.
But the chief palliative for the system is budget - the more advanced a network the less susceptible it is to an attack. Most emergency services setups are very tight on funds and security against the faint chance of an attack isn't as much of a priority as saving people's lives on a daily basis. ®