With a $300 Proxmark RFID card reading and writing tool, any expired keycard pulled from the trash of a target hotel, and a set of cryptographic tricks developed over close to 15 years of on-and-off analysis of the codes Vingcard electronically writes to its keycards, they found a method to vastly narrow down a hotel's possible master key code. They can use that handheld Proxmark device to cycle through all the remaining possible codes on any lock at the hotel, identify the correct one in about 20 tries, and then write that master code to a card that gives the hacker free reign to roam any room in the building. The whole process takes about a minute.
The two researchers say that their attack works only on Vingcard's previous-generation Vision locks, not the company's newer Visionline product. But they estimate that it nonetheless affects 140,000 hotels in more than 160 countries around the world; the researchers say that Vingcard's Swedish parent company, Assa Abloy, admitted to them that the problem affects millions of locks in total. When WIRED reached out to Assa Abloy, however, the company put the total number of vulnerable locks somewhat lower, between 500,000 and a million.
Patching is a nightmare. It requires updating the firmware on every lock individually.
And the researchers speculate whether or not others knew of this hack:
The F-Secure researchers admit they don't know if their Vinguard attack has occurred in the real world. But the American firm LSI, which trains law enforcement agencies in bypassing locks, advertises Vingcard's products among those it promises to teach students to unlock. And the F-Secure researchers point to a 2010 assassination of a Palestinian Hamas official in a Dubai hotel, widely believed to have been carried out by the Israeli intelligence agency Mossad. The assassins in that case seemingly used a vulnerability in Vingcard locks to enter their target's room, albeit one that required re-programming the lock. "Most probably Mossad has a capability to do something like this," Tuominen says.