Apple password gaffe revealed by Adelaide Uni researcher

Powered by SC Magazine
 

Lion passwords can be cracked or changed.

An Adelaide security researcher has blown the lid on an explosive Apple OS Lion flaw that allows passwords to be accessed and changed by anyone.

The flaw exists in the way passwords are stored and accessed as encrypted shadow files.

These files are accessible due to flaws in the file permission structure that is designed to allow only authorised local users and administrators access to the shadow files.

But the oversight allows anyone to skirt the permissions by looking up password hashes for all users that were stored in directory services.

Passwords can then be brute forced, or simply changed.

Security researcher Patrick Dunstan, a senior security information specialist at the University of Adelaide revealed on his Defence in Depth blog that the flaw allows OS X user password hashes and salts to be parsed.

“It appears in the redesign of OS X Lion's authentication scheme a critical step has been overlooked,” Dunstan said.

“So for all modern OS X platforms (Tiger, Leopard, Snow Leopard and Lion) each user has their own shadow file (hash database) whose data is accessible only by the root user… or at least it should be.

“Obtain the user's GeneratedUID and then use that ID to extract hashes from a specific user's shadow file.”

The holes go beyond vulnerabilities revealed by Dunstan in 2009 that allowed passwords to be cracked only via administrative accounts on pre- OS X 10.7 systems.

Dunstan created a Python script to assist in cracking the SHA512 + 4-byte salt OS X Lion hashes.

He said users can mitigate the attacks by limiting standard access to the command line DSCL utility using:

$ sudo chmod 100 /usr/bin/dscl

Sophos senior consultant Chester Wisniewski recommened users change passwords, enable a screensaver password prompt, and disable automatic logon.

He said the capability to change passwords was "particularly dangerous" if Apple's FileVault 2 disk encryption was used.

"If your Mac were left unlocked and someone changed your password, you would no longer be able to boot your computer and potentially would lose access to all of your data."

More information is available on Dunstan's blog.

Copyright © SC Magazine, Australia


Apple password gaffe revealed by Adelaide Uni researcher
 
 
 
Top Stories
Hockey flags billion-dollar Centrelink mainframe replacement
Claims 30 year-old tech is holding Govt back.
 
Ombudsman wants to monitor warrantless metadata access
Requests ability to report publicly.
 
Frugality as a service: the Amazon story
Behind the scenes, Amazon Web Services is one lean machine.
 
 
Sign up to receive iTnews email bulletins
   FOLLOW US...

Latest VideosSee all videos »

The great data centre opportunity on Australia's doorstep
The great data centre opportunity on Australia's doorstep
Scott Noteboom, CEO of LitBit speaking at The Australian Data Centre Strategy Summit 2014 in the Gold Coast, Queensland, Australia. http://bit.ly/1qpxVfV Scott Noteboom is a data centre engineer who led builds for Apple and Yahoo in the earliest days of the cloud, and who now eyes Asia as the next big opportunity. Read more: http://www.itnews.com.au/News/372482,how-do-we-serve-three-billion-new-internet-users.aspx#ixzz2yNLmMG5C
Interview: Karl Maftoum, CIO, ACMA
Interview: Karl Maftoum, CIO, ACMA
To COTS or not to COTS? iTnews asks Karl Maftoum, CIO of the ACMA, at the CIO Strategy Summit.
Susan Sly: What is the Role of the CIO?
Susan Sly: What is the Role of the CIO?
AEMO chief information officer Susan Sly calls for more collaboration among Australia's technology leaders at the CIO Strategy Summit.
Meet the 2014 Finance CIO of the Year
Meet the 2014 Finance CIO of the Year
Credit Union Australia's David Gee awarded Finance CIO of the Year at the iTnews Benchmark Awards.
Meet the 2014 Retail CIO of the Year
Meet the 2014 Retail CIO of the Year
Damon Rees named Retail CIO of the Year at the iTnews Benchmark Awards for his work at Woolworths.
Robyn Elliott named the 2014 Utilities CIO of the Year
Robyn Elliott named the 2014 Utilities CIO of the Year
Acting Foxtel CIO David Marks accepts an iTnews Benchmark Award on behalf of Robyn Elliott.
Meet the 2014 Industrial CIO of the Year
Meet the 2014 Industrial CIO of the Year
Sanjay Mehta named Industrial CIO of the Year at the iTnews Benchmark Awards for his work at ConocoPhillips.
Meet the 2014 Healthcare CIO of the Year
Meet the 2014 Healthcare CIO of the Year
Greg Wells named Healthcare CIO of the Year at the iTnews Benchmark Awards for his work at NSW Health.
Meet the 2014 Education CIO of the Year
Meet the 2014 Education CIO of the Year
William Confalonieri named Healthcare CIO of the Year at the iTnews Benchmark Awards for his work at Deakin University.
Meet the 2014 Government CIO of the Year
Meet the 2014 Government CIO of the Year
David Johnson named Government CIO of the Year at the iTnews Benchmark Awards for his work at the Queensland Police Service.
Q and A: Coalition Broadband Policy
Q and A: Coalition Broadband Policy
Malcolm Turnbull and Tony Abbott discuss the Coalition's broadband policy with the press.
AFP scalps hacker 'leader' inside Australia's IT ranks.
AFP scalps hacker 'leader' inside Australia's IT ranks.
The Australian Federal Police have arrested a Sydney-based IT security professional for hacking a government website.
NBN Petition Delivered To Turnbull's Office
NBN Petition Delivered To Turnbull's Office
UTS CIO: IT teams of the future
UTS CIO: IT teams of the future
UTS CIO Chrissy Burns talks data.
New UTS Building: the IT within
New UTS Building: the IT within
The IT behind tomorrow's universities.
iTnews' NBN Panel
iTnews' NBN Panel
Is your enterprise NBN-ready?
Introducing iTnews Labs
Introducing iTnews Labs
See a timelapse of the iTnews labs being unboxed, set up and switched on! iTnews will produce independent testing of the latest enterprise software to hit the market after installing a purpose-built test lab in Sydney. Watch the installation of two DL380p servers, two HP StoreVirtual 4330 storage arrays and two HP ProCurve 2920 switches.
The True Cost of BYOD
The True Cost of BYOD
iTnews' Brett Winterford gives attendees of the first 'Touch Tomorrow' event in Brisbane a brief look at his research into enterprise mobility. What are the use cases and how can they be quantified? What price should you expect to pay for securing mobile access to corporate applications? What's coming around the corner?
Ghost clouds
Ghost clouds
ACMA chair Chris Chapman says there is uncertainty over whether certain classes of cloud service providers are caught by regulations.
Was the Snowden leak inevitable?
Was the Snowden leak inevitable?
Privacy experts David Vaile (UNSW Cyberspace Law and Policy Centre) and Craig Scroggie (CEO, NextDC) claim they were not surprised by the Snowden leaks about the NSA's PRISM program.
Latest Comments
Polls
Which bank is most likely to suffer an RBS-style meltdown?





   |   View results
ANZ
  20%
 
Bankwest
  9%
 
CommBank
  12%
 
National Australia Bank
  17%
 
Suncorp
  23%
 
Westpac
  19%
TOTAL VOTES: 1516

Vote