The FileVault application on Apple computers can be cracked, revealing the user's master password, according to a password recovery company.

Passware - which produces and sells software designed to retrieve computer passwords - discovered the FileVault vulnerability and claims it can exploit it and gain access to a user's passwords in just 40 minutes.

The software, which is called Passware 11.3 and sells for $995, is run on a device that connects to a Mac's FireWire port; once connect to a booted-up and logged in Mac, PassWare accesses the computer's RAM, where it retrieves the master password.

FileVault has been included with Mac computers since OS X Panther was released in 2003 and was updated to FileVault 2 when OS X Lion was released in 2011; the application stores every password and username the computer's owner uses - including login details for email, websites like Facebook and Twitter, and Wi-Fi networks.

Passware intends its products to be used by authorities to gain access to computers for forensic research. The company said the new password cracking software "means forensic experts are better armed to approach investigative challenges with an effective and efficient solution that significantly reduces decryption time and, thus, allows investigators to focus on data analysis."

While it is unlikely that a common thief would spend the $995 for Passware and have nearly an hour with the victim's powered-up and logged-in computer, the findings still emphase that Mac users should not expect FileVault to offer them full protection.