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

Securing Web Applications Made Simple and Scalable

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. ®

Mobile application security vulnerability report

More from The Register

next story
NEW, SINISTER web tracking tech fingerprints your computer by making it draw
Have you been on YouPorn lately, perhaps? White House website?
HIDDEN packet sniffer spy tech in MILLIONS of iPhones, iPads – expert
Don't panic though – Apple's backdoor is not wide open to all, guru tells us
LibreSSL RNG bug fix: What's all the forking fuss about, ask devs
Blow to bit-spitter 'tis but a flesh wound, claim team
Black Hat anti-Tor talk smashed by lawyers' wrecking ball
Unmasking hidden users is too hot for Carnegie-Mellon
Manic malware Mayhem spreads through Linux, FreeBSD web servers
And how Google could cripple infection rate in a second
NUDE SNAPS AGENCY: NSA bods love 'showing off your saucy selfies'
Swapping other people's sexts is a fringe benefit, says Snowden
Own a Cisco modem or wireless gateway? It might be owned by someone else, too
Remote code exec in HTTP server hands kit to bad guys
prev story

Whitepapers

Reducing security risks from open source software
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Application security programs and practises
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.