Feeds

Firefox leak could divulge sensitive info

How to remotely share your settings with people you've never met

Seven Steps to Software Security

A security researcher has discovered a vulnerability in Firefox that could allow criminals to remotely siphon private information stored in plugins and call sensitive functions.

According to an entry on the 0x000000 blog, Firefox generously enumerates all variables and registered objects that are present inside javascript files and on runtime and even allows the calling of certain functions.

This means ethically challenged hackers can remotely scan all variables set in Firefox plugins and use a simple AJAX script to log that information on a server.

While the ability to call functions stored in various plugins opens the possibility of denial-of-service attacks, the bigger risk from the vulnerability is that it will disclose information that could seriously compromise a user's privacy.

We're thinking of information stored in the Adblock plugin, for example. It includes a list of sites that have been whitelisted or blacklisted, giving snoops insights about a user's browsing habits. Even more problematic, would be details stored in extensions such as Gmail Checker or Boost for Facebook and dozens of other add-ons that personalize third-party websites.

"Depending on exactly what plugins you have installed it could be a problem," said Charlie Miller, principal security analyst for Independent Security Evaluators, who reviewed the 0x000000 blog post. "Using this particular vulnerability you could actually iterate and see what plugins are installed, which would be helpful if one of the plugins revealed information you wanted."

Miller was unable to access Adblock whitelist information using Proof-of-concept code 0x000000 made available, but he says that's likely a limitation of the code, not the vulnerability.

"I suspect its possible to get that information from the exploit," he told The Reg.

A Mozilla spokesman said the organization is investigating the report. As usual, the best workaround in the interim is NoScript, provided the site exploiting site has not been authorized to run javascript. ®

Mobile application security vulnerability report

More from The Register

next story
Yorkshire cops fail to grasp principle behind BT Fon Wi-Fi network
'Prevent people that are passing by to hook up to your network', pleads plod
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
NEW, SINISTER web tracking tech fingerprints your computer by making it draw
Have you been on YouPorn lately, perhaps? White House website?
LibreSSL RNG bug fix: What's all the forking fuss about, ask devs
Blow to bit-spitter 'tis but a flesh wound, claim team
Attackers raid SWISS BANKS with DNS and malware bombs
'Retefe' trojan uses clever spin on old attacks to grant total control of bank accounts
Manic malware Mayhem spreads through Linux, FreeBSD web servers
And how Google could cripple infection rate in a second
Mozilla fixes CRITICAL security holes in Firefox, urges v31 upgrade
Misc memory hazards 'could be exploited' - and guess what, one's a Javascript vuln
Don't look, Snowden: Security biz chases Tails with zero-day flaws alert
Exodus vows not to sell secrets of whistleblower's favorite OS
prev story

Whitepapers

Designing a Defense for Mobile Applications
Learn about the various considerations for defending mobile applications - from the application architecture itself to the myriad testing technologies.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
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.
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.