Feeds

Using Android 4.3? Don't let malware snatch your private login keys

Bad news: One in ten devices suffer KeyStore flaw. Good news: It's hard to exploit

Top 5 reasons to deploy VMware with Tegile

If you're one of the 10.3 per cent of Android users running version 4.3, aka Jelly Bean, your login keys are at risk of theft – thanks to a vulnerability in the operating system's KeyStore software.

KeyStore, as the name suggests, stores a user's cryptographic keys, which are used by apps to log into services without the user having to retype their password.

But IBM researchers have found that the program is vulnerable to a classic stack-based buffer overflow by an attacker who is able to get a dodgy app running on a device. By borking KeyStore, some secure login functions could be accessed and master keys obtained.

The team notes that Google's KeyStore source code contains this harbinger of the vulnerability in the comments: "To keep things simple, buffers are always larger than the maximum space we needed, so boundary checks on buffers are omitted."

Unfortunately, applications can set the size of the data processed, meaning the buffers are not always large enough, and malicious software can therefore inject bytes into the KeyStore app's memory where it shouldn't. From there, the attacking code will try to hijack the flow of execution in KeyStore.

However, before people panic, the IBM advisory does explain that the flaw is a particularly tricky one to exploit.

An attacker would need to write an app that contained malware, convince the user to download and install it, and then evade multiple security defenses – DEP, ASLR and stack cookies – to exploit the buffer overflow and execute code within the KeyStore process. And even then some of the KeyStore information is still protected.

The IBM researchers found the flaw last September and alerted the Android security team privately about the issue. By November a fix was developed for Android 4.4, but not the Jelly Bean build, so the team sat on the problem a while longer before disclosing it.

"Considering Android’s fragmented nature and the fact that this was a code-execution vulnerability, we decided to wait a bit with the public disclosure," said Roee Hay, IBM's application security research team lead, in a blog post about the hole. ®

Internet Security Threat Report 2014

More from The Register

next story
'Kim Kardashian snaps naked selfies with a BLACKBERRY'. *Twitterati gasps*
More alleged private, nude celeb pics appear online
Hackers pop Brazil newspaper to root home routers
Step One: try default passwords. Step Two: Repeat Step One until success
UK.gov lobs another fistful of change at SME infosec nightmares
Senior Lib Dem in 'trying to be relevant' shocker. It's only taxpayers' money, after all
Spies would need SUPER POWERS to tap undersea cables
Why mess with armoured 10kV cables when land-based, and legal, snoop tools are easier?
TOR users become FBI's No.1 hacking target after legal power grab
Be afeared, me hearties, these scoundrels be spying our signals
Snowden, Dotcom, throw bombs into NZ election campaign
Claim of tapped undersea cable refuted by Kiwi PM as Kim claims extradition plot
Freenode IRC users told to change passwords after securo-breach
Miscreants probably got in, you guys know the drill by now
THREE QUARTERS of Android mobes open to web page spy bug
Metasploit module gobbles KitKat SOP slop
BitTorrent's peer-to-peer chat app Bleep goes live as public alpha
A good day for privacy as invisble.im also reveals its approach to untraceable chats
prev story

Whitepapers

Secure remote control for conventional and virtual desktops
Balancing user privacy and privileged access, in accordance with compliance frameworks and legislation. Evaluating any potential remote control choice.
Intelligent flash storage arrays
Tegile Intelligent Storage Arrays with IntelliFlash helps IT boost storage utilization and effciency while delivering unmatched storage savings and performance.
WIN a very cool portable ZX Spectrum
Win a one-off portable Spectrum built by legendary hardware hacker Ben Heck
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Beginner's guide to SSL certificates
De-mystify the technology involved and give you the information you need to make the best decision when considering your online security options.