Feeds

Firefox's Greasemonkey slippery on security

Full file exposure

  • alert
  • submit to reddit

The Essential Guide to IT Transformation

A severe security hole in Firefox's Greasemonkey extension has been uncovered that exposes any file on a user's local hard drive to a hacker.

The vulnerability affects PCs and Macs and means a hacker does not need to know an exact file name before diving into a system. According to one online posting, typing something such as "file:///c:/" will return a parseable directory listing. Macs can be hacked in a similar way.

Mark Pilgrim, a coder and author writing about Greasemoney, told a Greasemonkey mailing list: "This particular exploit is much, much worse than I thought. GM_xmlhttpRequest can successfully "GET" any world readable file on your local computer.

"And because GM_xmlhttpRequest can use POST as well as GET, an attacker can quietly send this information anywhere in the world," Pilgrim warned.

Greasemonkey enables developers to add DHTML to a web page, in order to change that page's behavior.

Users have been advised to either completely un-install the Greasemonkey extension or downgrade to Greasemonkey to 0.3.5 - a "neutered" version that lacks the APIs making Greasemonkey scripts more powerful than regular HTML.

A fix is in development and expected to take a few days, according to Greaseblog - the Greasemonkey blog®

Related stories

Hackers attack Mozilla site to spread spam
Firefox update completes busy patching day
Firefox spoof bug returns from the dead

Build a business case: developing custom apps

More from The Register

next story
14 antivirus apps found to have security problems
Vendors just don't care, says researcher, after finding basic boo-boos in security software
'Things' on the Internet-of-things have 25 vulnerabilities apiece
Leaking sprinklers, overheated thermostats and picked locks all online
iWallet: No BONKING PLEASE, we're Apple
BLE-ding iPhones, not NFC bonkers, will drive trend - marketeers
Only '3% of web servers in top corps' fully fixed after Heartbleed snafu
Just slapping a patched OpenSSL on a machine ain't going to cut it, we're told
How long is too long to wait for a security fix?
Synology finally patches OpenSSL bugs in Trevor's NAS
Israel's Iron Dome missile tech stolen by Chinese hackers
Corporate raiders Comment Crew fingered for attacks
Tor attack nodes RIPPED MASKS off users for 6 MONTHS
Traffic confirmation attack bared users' privates - but to whom?
Roll out the welcome mat to hackers and crackers
Security chap pens guide to bug bounty programs that won't fail like Yahoo!'s
Researcher sat on critical IE bugs for THREE YEARS
VUPEN waited for Pwn2Own cash while IE's sandbox leaked
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Boost IT visibility and business value
How building a great service catalog relieves pressure points and demonstrates the value of IT service management.
Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.
The Essential Guide to IT Transformation
ServiceNow discusses three IT transformations that can help CIO's automate IT services to transform IT and the enterprise.
Maximize storage efficiency across the enterprise
The HP StoreOnce backup solution offers highly flexible, centrally managed, and highly efficient data protection for any enterprise.