Apple acknowledged has a major security flaw in its software for mobile devices and most users aren’t aware of just how at risk they might be if they fail to update their software. Mac computers could be even more exposed to attacks.

A Secure Socket Layer (SSL) vulnerability allowing hackers to intercept information that is supposed to encrypted. If an attacker hsd access to the same network over an unsecured WiFi connection then he could impersonate a protected site such as Facebook or Gmail and alter any data passed between the iPhone and the site.

Johns Hopkins University cryptography professor Matthew Green summarized it succinctly to Reuters: “It’s as bad as you could imagine, that’s all I can say.”