Apple Security Update 2004-06-07

In late May 2004 there was a flurry of discussion stimulated by the discovery of a group of related security holes in OS X; these all involved exploits that were made possible by the operating system's handling of various URLs. I discovered one of the vulnerabilities myself: for users whose computers happen to be configured a certain way, the system's handling of the ssh:// protocol can lead to the execution of arbitrary code.

Today's Security Update from Apple attempts to address some of these problems by patching the system so that it will alert the user when the invocation of a URL will lead to the launching of an application that has not been manually launched before. This helps to fix some of the exploits, but does not address some of the others: in particular, you are still potentially vulnerable to the telnet:// exploit (that may be used to overwrite files) and the ssh:// exploit. As before, the best and simplest fix is simply to disable the dangerous protocols.