Twitter on Wednesday fell foul of a potential security weakness that lies at the heart of “cloud”, or internet-based, software applications, leading to the leak of a raft of internal documents from the internet start-up.

The leaked documents included a forecast of Twitter’s projected annual revenues in 2013. It was one of more than 300 internal Twitter documents that TechCrunch, the online news site, said it had been sent by an anonymous hacker.