Researcher nets $20K for finding serious Facebook flaw

The problem, now fixed, could have allowed anyone to take over a person's account

A U.K.-based researcher has netted US$20,000 for spotting a very serious flaw in Facebook that could have allowed an attacker to take over anyone's account with minimal effort.

The flaw was fixed by Facebook about a month ago, wrote Jack Whitten, an application security engineer who posted a post-mortem on his blog.

Whitten found it was possible to reset the password of anyone's account by exploiting an error in how Facebook lets users link their mobile phone to their account for purposes such as receiving updates over SMS.

Facebook sends a verification code by SMS when a user registers a phone. But Whitten found it was possible to modify the "profile_id" field within the mobile confirmation form to that of a different user.

Facebook then asks for a password but not the one of the potential victim, Whitten wrote. The account of the victim is then inadvertently linked with the attacker.

Whitten then initiated a password reset on the victim's account. The code needed to reset that password was sent to Whitten's phone, along with a link to a password reset page.

"We enter this code into the form, choose a new password, and we're done. The account is ours," Whitten wrote.

A flaw such as the one found by Whitten would have had value among cyberattackers seeking to abuse Facebook accounts for spam or for the theft of personal data.

"The bounty assigned to this bug was $20,000, clearly demonstrating the severity of the issue," he wrote.

Whitten, who goes by the screen name "fin1te," has been recognized for finding vulnerabilities by Google, Facebook and Etsy.

Send news tips and comments to jeremy_kirk@idg.com. Follow me on Twitter: @jeremy_kirk

Join the Good Gear Guide newsletter!

Error: Please check your email address.
Rocket to Success - Your 10 Tips for Smarter ERP System Selection

Tags securityExploits / vulnerabilitiesFacebook

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Jeremy Kirk

IDG News Service
Show Comments

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Matthew Stivala

HP OfficeJet 250 Mobile Printer

The HP OfficeJet 250 Mobile Printer is a great device that fits perfectly into my fast paced and mobile lifestyle. My first impression of the printer itself was how incredibly compact and sleek the device was.

Armand Abogado

HP OfficeJet 250 Mobile Printer

Wireless printing from my iPhone was also a handy feature, the whole experience was quick and seamless with no setup requirements - accessed through the default iOS printing menu options.

Azadeh Williams

HP OfficeJet Pro 8730

A smarter way to print for busy small business owners, combining speedy printing with scanning and copying, making it easier to produce high quality documents and images at a touch of a button.

Andrew Grant

HP OfficeJet Pro 8730

I've had a multifunction printer in the office going on 10 years now. It was a neat bit of kit back in the day -- print, copy, scan, fax -- when printing over WiFi felt a bit like magic. It’s seen better days though and an upgrade’s well overdue. This HP OfficeJet Pro 8730 looks like it ticks all the same boxes: print, copy, scan, and fax. (Really? Does anyone fax anything any more? I guess it's good to know the facility’s there, just in case.) Printing over WiFi is more-or- less standard these days.

Ed Dawson

HP OfficeJet Pro 8730

As a freelance writer who is always on the go, I like my technology to be both efficient and effective so I can do my job well. The HP OfficeJet Pro 8730 Inkjet Printer ticks all the boxes in terms of form factor, performance and user interface.

Michael Hargreaves

Windows 10 for Business / Dell XPS 13

I’d happily recommend this touchscreen laptop and Windows 10 as a great way to get serious work done at a desk or on the road.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?