Cracker takes control of 200 rooms in Chinese hotel
Blinds go up, blinds go down, hotel manager has no idea why
Black Hat 2014 A security consultant staying in the St Regis hotel in the Chinese city of Shenzhen got bored one night and successfully commandeered the controls of 200 rooms thanks to an insecure automation protocol.
Jesus Molina, a former chair of the Trusted Computing Group and independent security consultant, was staying in the hotel and started playing around with the in-room iPad which was used to control the lights and blinds. Each room has its own iPad and Molina started thinking about how the system worked.
Firstly he noticed that the version of iOS running the in-room iPad wasn't locked down, and that it used the hotel’s guest internet service to communicate with the fixtures and fittings. He also spotted that the automation commands used a protocol called KNX/IP.
KNX/IP was originally put together in 1990 and has no security settings. Yet it is the standard for hotel device automation in China and is also widely used in Europe. A new version with some security built in has been developed but most users haven’t updated.
One possible reason for this is that KNX/IP claims to be an open standard, but the documentation on how to use it costs €1,000, Molina said. Since he didn't have that kind of cash lying around Molina decided to do some digging of his own.
By examining the system he discovered that simply by changing the last digit of a devices IP address he could take over another device. He then wrote a script on the iPad which appeared to map out the IP addresses for lights and blinds in 200 rooms.
To test out his theory Molina called the front desk, said he wasn't happy with his room and asked to be moved to a new one. After doing this four times (earning a stern talking to from the hotel manager) he got a good enough read to map out the hotel’s network.
"I thought about looking to see if a similar system controlled the door locks but got scared," he told his audience at the Black Hat hacking conference.
Molina then got in touch with the St Regis' parent company and informed them of the flaw. The system has now been fixed, he said, put plenty of other hotels might be vulnerable. ®