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Mac OS X Root Escalation Through AppleScript
An anonymous reader writes "Half the Mac OS X boxes in the world (confirmed on Mac OS X 10.4 Tiger and 10.5 Leopard) can be rooted through AppleScript: osascript -e 'tell app "ARDAgent" to do shell script "whoami"'; Works for normal users and admins, provided the normal user wasn't switched to via fast user switching. Secure? I think not." On the other hand, since this exploit seems to require physical access to the machine to be rooted, you might have some other security concerns to deal with at that point, like keeping the intruder from raiding your fridge on his way out.
Could somebody explain how running a script requires physical access?
A proud member of the Onion-in-Hand alliance
It seems perfectly serious since one of the main security aspects of OS X is that root access is held sacred (as it should be) and malware is assumed to be 'stopped at the gate' by that policy.
But Apple have made exactly the same marketing mistakes that Microsoft did in selling their respective OSes as ones that can be used easily by people with no knowledge of computers - people still click on attachments they shouldn't, still give their passwords to phishing web sites and still don't install regular security updates and scan their PCs for virii.
And in the case of this specific exploit, I am sure that a number of newbie Apple users would happily tap in "osascript -e 'tell app "ARDAgent" to do shell script "whoami"'" into their computers purely because "Jim The Friendly Computer Support Engineer" told them to do it.
So let's not beat about the bush - ANY exploit that isn't fixed as quickly as possible is a problem because there's always at least one spotty teenager trying to become a HAX0R who is prepared to try his luck against some poor unwitting user.
Gentoo Linux - another day, another USE flag.
First, yes, this is a serious bug. It's a classic blunder, like getting into a land war in Asia, and is similar to the in NT3.51's scheduler to get LOCALSYSTEM rights, or the one in /bin/write in 2BSD to get a root shell.
It's also easy to fix.
And I am about 99 44/100 percent sure that there's more undiscovered holes like this in OS X, Windows Vista, and any random Linux desktop you could name.
THe thing is, it's not true that "one of the main security aspects of OS X is that root access is held sacred (as it should be) and malware is assumed to be 'stopped at the gate' by that policy". It's not. You can protect the OS from the malware, but the malware can still hide, still restart itself after a reboot, and still destroy everything you actually CARE about without root access. And malware can similarly break out of Vista's jail around IE, and whatever APple does along those lines.
Security is like sex. Once you're penetrated you're ****ed.
The biggest advantage that Apple has is that Safari doesn't (any more) have a mechanism (at least not by default) to blithely execute outside a *closed* sandbox (not a leaky one) any random malware that can convince it that it's safe and trusted. That's the biggest security problem Windows has. ActiveX and all its kin. It's harder to penetrate OS X in the first place... you pretty much have to depend on social engineering... and people CAN learn not to be social-engineered.
This code could easily be wrapped into the preflight scripts for an Installer package in OS X, or integrated into any piece of malware to escalate itself to root without any user interaction beyond downloading it and launching it. In this sense, the arguments against the DNSChanger Trojan Horse of "it requires an admin password to be installed" becomes null and void. This is fairly serious, folks. One-click privilege escalation is way too easy for script-kiddies and professional malware distributers alike to integrate into their nasty programs.
No, what's good about Linux, and to a slightly lesser extend OSX, is that Unix is an incredibly simple system at it's core, so there are relatively few possible exploitation vectors and they are all well understood.
:)
Unfortunately KDE, Qt, X11, Gtk, Gnome, and the whole "let's make Linux into Windows" desktop hodgepodge that's layered on top of UNIX[1] is incredibly complex, has many components running with elevated privileges, and while it has fewer exploitation vectors than Windows it's conceptually more complex than the NeXTstep-derived equivalents in OS X.
And on top of that, many linux distros have resurrected the absolutely insane concept of Autorun CDs, something Apple was smart enough to abandon back in the dark ages of floppy distribution.
So, all in all, "do not be so proud of this technological terror". I'd go on, but I've got work to do.
[1] No, X11 is not really a UNIX API, it was designed to be platform independent, ran on UNIX and VMS from the start, and completely ignores many of the fundamental design goals of UNIX as well as many of the most useful *results* of those design goals.
On the other hand, since this exploit seems to require physical access to the machine to be rooted, you might have some other security concerns to deal with at that point, like keeping the intruder from raiding your fridge on his way out.
What about non personal deployments?
Like corporate installations?
Kiosk installations?
Any small business that wants to secure a machine?
How about a class room that you want kiddies to run games but not wipe the OS?
Physical access MEANS if they can access the hardware (inside the case). It DOES NOT mean typing something on the freaking keyboard, when logged in as a low level user.
In the IT world you password lock boot media, lock cases,etc. If an IT person can't secure a machine without removing the keyboard, there MIGHT be a security problem.
(SlashDot Editors? WTF?)
Also, who says Apple wasn't notified of this problem in advance? I'm not saying they were or weren't, but I don't have data either way. This is the same community that loves to lambast Microsoft for their security issues (rightly so, in most cases), but fully supports immediate disclosure of exploits before patches are released by Microsoft (although MS has taken forever to fix many problems). As a network admin, I'm a fan of full disclosure, which gives the ability to do something about the issue until a patch is released. Others see things differently.
512 MB RAM, 20 GB disk, 200 GB transfer, five datacenters. $19.95/month.
Your average optical drive is rather expensive to use as a CD case you know.
Advanced users are users too!
The reason that requiring physical access is seen as no big deal is because all that stuff you're worried about is something I can do without the need of any exploits.
Got a machine with literally any operating system? All I need is to reboot the computer with a linux live cd (or usb thumb drive) and I get read / write access to everywhere. From there I can plant trojans, read your files, do whatever.
Got a Linux machine? I can reboot and use grub to boot into single-user mode. There you go, I'm root. I can do all the of the above again.
The only way to have any security at the physical level is with encryption. And when we see encryption exploits, we do get hyped up about it. Even with encryption, more security measures still need to be taken at the physical level. A physical keylogger between the keyboard and computer could be installed to discover typed passwords, etc.
That said, an exploit is an exploit, and it should be treated as such. Physical-access only just means there's less to worry about.
Warning: Opinions known to be heavily biased.