The hole, which was rated as "extremely critical" by security company Secunia, allowed an attacker to potentially execute any Unix command, including ones to erase the users home directory.
The company took the unusual step of issuing a statement announcing the fix, in contrast to its previous policy of refusing all comment on security issues.
"Apple takes security very seriously and works quickly to address potential threats as we learn of them—in this case, before there was any actual risk to our customers," said Philip Schiller, Apple Computer Inc.s senior vice president of worldwide product marketing.
But according to some users, the company was notified of the problem in February and has yet to respond to the original notification.
The fix is available via the Mac OS X Software Update System Preference, or it can be downloaded from Apples Web site.