Apple fixes downloads vulnerability

Daily Newsletters

Sign up to ZDNet UK's daily newsletter.

NEWS
Apple has released a patch for a glaring security hole in its software update system, which made it a trivial matter to install a back door into any Mac running OS X, according to security experts. On Friday the company released an upgrade to its Software Update for Mac OS X that introduces an authentication process for the automatic download system. Last week, hacker Russell Harding, who claimed to have discovered the exploit, made available two programs that he said had been customised to carry out an attack via Software Update. Apple's download is available to systems running Mac OS X 10.1 or later, via the Software Update system itself or Apple's Web site. The secure Web page includes optional instructions for verifying that the package is authentic -- which some hackers said they preferred, given the nature of the security glitch. "Packages presented via the Software Update mechanism are now cryptographically signed, and the new Software Update client 1.4.6 checks for a valid signature before installing new packages," Apple said on the site. "Downloaded packages which do not contain a valid signature are deleted from the system." According to Harding, versions 1.4.5 and earlier of Software Update downloads updates over the HTTP protocol with no authentication, and installs them as root on the system. It is a simple matter, according to Harding, to use any one of several well-known techniques to trick a user into installing a malicious program posing as an update from Apple. Such techniques include DNS spoofing and DNS Cache Poisoning. When a previous version of Software Update runs, it connects via HTTP to an Apple.com page and sends a simple request for an XML document, which returns a list of software and current versions for OS X to check, according to Harding. After the check, OS X sends a list of its currently installed software to another page on Apple.com. If new software is available, the Software Updates Server responds with the location of the software, size, and a brief description. If not, the server sends a blank page with the comment "No Updates". Harding made available two programs that he said were been customised for carrying out this attack. One program listens for DNS queries for updates, and when it receives them replies with spoofed packets re-routing them to the attacker's computer. The second program, which is downloaded onto the victim's Mac masquerading as a security update, in fact contains a "back-doored" copy of the Secure Shell Server Daemon, sshd. "This version of sshd includes all the functions of the stock sshd," wrote Harding, "except the following: You can log in to any account on the system with the secret password 'URhacked!'. After logging in through this method, no logging of the connection is employed. In fact, you do not show up in the list of current users!" Automatic updates of software -- particularly operating system software -- is a growing trend. Several Linux companies offer this feature for their distributions of the open-source operating system, and Microsoft recently launched a similar service called Microsoft Software Update Services. Matt Loney contributed to this report.
For all security-related news, including updates on the latest viruses, hacking exploits and patches, check out ZDNet UK's Viruses and Hacking News Section. Have your say instantly, and see what others have said. Go to the Security forum. Let the editors know what you think in the Mailroom.

Post your comment

In order to post a comment you need to be registered and logged in.

You can also log in with Facebook. Log in or create your ZDNet UK account below

  • Login

Will not be displayed with your comment

By signing up for this service, you indicate that you agree to our Terms and Conditions and have read and understood our Privacy Policy. Questions about membership? Find the answers in the Community FAQ

Get ZDNet UK's daily newsletter

Enter your email address to sign up

ZDNet UK Live

TerryRK

Isn't the provision of a text based search an admission by the developers that the mass of icons approach does not work? I don't need to use a...

1 hour ago by TerryRK on A tale of two distros: Ubuntu and Linux Mint
kevinmchapman

"Unity and GNOME 3 both abandon the old text-based cascading menus in favour of a graphical icon-driven system." Point truly missed. Both use a...

2 hours ago by kevinmchapman on A tale of two distros: Ubuntu and Linux Mint
TerryRK

whs001 - Thank you, I'm glad you liked the article. I absolutely agree with you on your first point. I should perhaps have made it clearer that...

2 hours ago by TerryRK on A tale of two distros: Ubuntu and Linux Mint
Dennis Nilsson

If we allow corporate interest to dictate the way our government circumvents due process against foreign entities then we should accept the same...

3 hours ago by Dennis Nilsson via Facebook on ACTA stumbles in Germany
GHar123

I totally dislike pirating of works, I fear that artists will be deterred from creating works if they think that they are going to get ripped off....

4 hours ago by GHar123 on ACTA stumbles in Germany
JCB33

How dare film makers, artists or anybody that invests in creativity stop us pirating their works for free. I want to be able to walk into my local...

10 hours ago by JCB33 on ACTA stumbles in Germany
Moley

@GrueMaster. I prefer horses for courses rather than one size fits all. I, and I suspect most other computer users, do not really wish to have...

12 hours ago by Moley on A tale of two distros: Ubuntu and Linux Mint
greycynic

The product that scares me every time I have to use it is the Office 2007 version of Excel. The first bug that I found was applying the median...

12 hours ago by greycynic on Ten flawed products that derail productivity
GrueMaster

Nice review and very informative. One thing I'd like to add (in reply to whs001's 1st question), the main reason to have the same interface from...

14 hours ago by GrueMaster on A tale of two distros: Ubuntu and Linux Mint
Frederick Wrigley

I'be been using Mint 12 since the RC came out, and I am far more happy with the Cinnamon, the Mate, and, yes (with extensions), theGnome 3...

15 hours ago by Frederick Wrigley via Facebook on A tale of two distros: Ubuntu and Linux Mint
bdantas

Excellent article. One small correction, though--although a fresh installation of Linux Mint 12 will, indeed, provide the user with a version of...

15 hours ago by bdantas on A tale of two distros: Ubuntu and Linux Mint
Alan Ralph

In related news, the ISPs club together to get the members of the Home Affairs Select Committee (ya goofed on that part, ZDNet UK) copies of "The...

16 hours ago by Alan Ralph via Facebook on MPs urge ISPs to take down terrorist material
Alan Ralph

In related news, the ISPs club together to get the members of the Home Affairs Select Committee (ya goofed on that part, ZDNet UK) copies of "The...

16 hours ago by Alan Ralph via Facebook on MPs urge ISPs to take down terrorist material
Moley

For Gnome 2 die-hards, it is possible to add icons to the bottom panel (or top top panel, if you prefer) which provide the exact Gnome 2...

17 hours ago by Moley on A tale of two distros: Ubuntu and Linux Mint
ramwellian

Your comments would seem pretty naive and immature. Your 'solution' appears to be, "gee, let's all just give in to the hackers and give them...

17 hours ago by ramwellian on Cloud computing security: no more oxymoron?
BugStalker

"Interesting thought ... If you installed Win7 as a dual boot on a machine that previously only had Linux, and it wrecked your Linux installation,...

17 hours ago by BugStalker on Windows 7 Declares War on GRUB
whs001

This is an excellent summary of Ubuntu and Mint and the interface differences between them. Most such articles take a very partisan position for...

17 hours ago by whs001 on A tale of two distros: Ubuntu and Linux Mint
Moley

@ewallace. Not so clear. Anyone can obtain the text, for example from here http://www.ustr.gov/webfm_send/2379. I support ACTA so long as it and...

17 hours ago by Moley on ACTA: Facts, misconceptions and questions
45283

I think WinRT is fantastic. I just wish it was an option for people that didn't want to go through Microsoft's App Store with its attendant...

21 hours ago by 45283 on Why Windows 8 needs architectural hygiene for WOA
Burn-IT

Nine people? £30m? Who's back pocket is that lot going in? And IF they say it is for new buildings, what about all the ones the government has...

22 hours ago by Burn-IT on Police set to launch three £30m e-crime hubs