An Apple programmer has accidentally left a debug flag in the most recent version of OS X Lion, which under certain conditions can cause login passwords to appear in a plain text debug log file, reports ZDNet.
The flaw affects users who have used Apple's encryption software FileVault prior to upgrading to 10.7.3, while FileVault 2 is unaffected.
To make matters worse, Apple has not issued a fix for the matter, so changing your user credentials right now does not help, as those credentials might end up in a debug log file as well.
The flaw, which was originally spotted by a security researcher David Emery, potentially enables anyone with an admin password to retrieve other user's credentials.
"This is worse than it seems, since the log in question can also be read by booting the machine into firewire disk mode and reading it by opening the drive as a disk or by booting the new-with-LION recovery partition and using the available superuser shell to mount the main file system partition and read the file. This would allow someone to break into encrypted partitions on machines they did not have any idea of any login passwords for," claims Emery.