Customers of cahoot, the UK internet bank, were able to view other people's accounts after an upgrade to the service went awry.
The service, taken down for 10 hours yesterday to resolve the security breach, is now back up and running. cahoot said the problem is fixed and lessons have been learned. The glitch meant cahoot users could view the account of other subscribers, so long as they knew their customer IDs. But it was not possible to transfer money from these accounts without also knowing the password of potential victims, according to cahoot.
In a statement, the bank said: "This problem has arisen as a result of a change cahoot made to its IT system several days ago. As soon as we discovered it, we closed the site while we did testing and sorted out a solution. It has now been fixed and thoroughly tested."
"At no time were customers in danger of having money taken out of their accounts because of this systems glitch, but cahoot takes all security issues extremely seriously indeed, and has acted quickly to put this right," it added.
The upgrade took place 12 days ago, but the problem came to light after an investigation by BBC Breakfast, acting on a tip-off from a concerned viewer.
IT penetration testing company SecureTest said the security breach at cahoot is just one example of a growing category of application security problems.
"The network, the hardware and the infrastructure can all be as close to 100 per cent secure as is possible, but if applications contain flaws this is all useless," said Ken Munro, SecureTest's managing director. "In many cases 'hacking' is almost too strong a word. Five minutes spent online, reading-up on input validation and session management attacks, would allow most people to access sensitive information on many of these websites. Or in the case of cahoot, after a poorly managed upgrade to an application, people can even stumble on information by accident." ®