Feeds

Mozilla security chief confirms data leakage bug in Firefox

Help on the way

Using blade systems to cut costs and sharpen efficiencies

Mozilla's chief of security has confirmed a vulnerability that could cause fully patched versions of Firefox to expose a user's private data.

The confirmation, which was posted here by Mozilla's Window Snyder, follows the release of proof-of-concept code by researcher Gerry Eisenhaur.

The bug resides in Firefox's chrome protocol scheme and allows for a directory traversal when certain types of extensions are installed. Attackers could use it to detect if certain programs or files are present on a machine, gaining information to use in perpetrating another, more malicious exploit.

Normally, Firefox's chrome package is restricted to a limited number of directories, but a bug in the way it handles escaped sequences (i.e. %2e%2e%2f) allows attackers to escape those confines and access more sensitive parts of a user's computer. The exploit only works if a user has made use of Firefox extensions that are "flat," this is, those that don't package their files in a jar archive. Examples of flat add-ons include Download Statusbar and Greasemonkey.

Mozilla bug squashers have rated the severity as normal and are working on a fix. In the meantime, Firefox users can protect themselves by using the NoScript extension, which will prevent the traversal attacks from working. ®

Story updated to correct information about NoScript.

The smart choice: opportunity from uncertainty

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
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
Don't look, Snowden: Security biz chases Tails with zero-day flaws alert
Exodus vows not to sell secrets of whistleblower's favorite OS
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

Seven Steps to Software Security
Seven practical steps you can begin to take today to secure your applications and prevent the damages a successful cyber-attack can cause.
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.
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.
Build a business case: developing custom apps
Learn how to maximize the value of custom applications by accelerating and simplifying their development.
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.