ZDNet reports on the discovery of a significant breach of password security for certain users of Apple's FileVault encryption system under OS X Lion. Affected systems currently store the login information for every recent user of the machine in plain text, allowing for easy circumvention of encryption.
In specific configurations, applying OS X Lion update 10.7.3 turns on a system-wide debug log file that contains the login passwords of every user who has logged in since the update was applied. The passwords are stored in clear text.
Anyone who used FileVault encryption on their Mac prior to Lion, upgraded to Lion, but kept the folders encrypted using the legacy version of FileVault is vulnerable. FileVault 2 (whole disk encryption) is unaffected.
The issue was noted last Friday by David Emery on the Cryptome mailing list.
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.
Emery also offers some suggestions for dealing with the issue, including turning on FileVault 2 and setting a firmware password on the machine in question.
The issue was actually first noted in the Apple discussion forums back on February 6, just days after OS X 10.7.3 was released to the public. That poster now notes that the issue may extend further than just the specific FileVault situation outlines by others, as he notes that he has experienced the same behavior on an OS X Lion virtual machine through VMware Fusion, without FileVault ever having been active on the installation. Consequently, the extent of the issue may not yet be fully known.
Apple has yet to offer any response to the issue, although it is unclear when the company became aware of it. Apple touts the security features of OS X Lion in its promotional materials for the operating system, with a focus on FileVault as an important component of that security, and it seems likely that the company will move as quickly as possible to investigate and fix the issue.
Top Rated Comments
This is not a non-issue. Don't be an apologist. There are legitimate reasons to use FileVault v1 over v2. v1 encrypts your home directory while v2 encrypts the whole filesystem. If you have untrusted users on the same computer (say shared with a family) v2 will give other users full access to your files while v1 will encrypt on a per home directory basis and another user will be unable to see your files.
Even if there were no legitimate reason to use v1 over v2 that is still no excuse. This is a serious oversight with serious consequences. Now these kind of things happen and the fact that it happened is not an insult to Apple. However, there is no excuse for it going unpatched for this long. There should have been a patch immediately after it was discovered. There is no excuse for that.
I just feel like I'm seeing more stories like this these days than I did in past years.
It's been stated Jobs hated hiring more, and kept a tight knit group of engineers. Perhaps more would help alleviate/diminish the odds of such programming flaws. Who knows. Either way, I'm sure it wouldn't hurt.
Agree. From what I gather, engineers are strained, being spread across iOS OS X departments. In part to unify the group but also in keeping with Jobs' desire for a small engineering base. It seems to be negatively effecting some aspects to their OS's.
That's not true. Any admin user can spawn a root shell without the root password.
turtle@vier ~ $ whoami
turtle
turtle@vier ~ $ sudo su
vier turtle # whoami
root
vier turtle #
No password required other than the admin user password. That's not the point anyway, system passwords should not be logged in clear text period. Again, the fact that this happened isn't as big of a problem as the fact that it hasn't been patched yet.