Dark Reading is part of the Informa Tech Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them.Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.


10:19 PM
Connect Directly

Facebook Apps Leaked Access To User Profiles, Pictures, Chats

Symantec discovers application security hole, Facebook closes it -- and Congress wants answers

Researchers at Symantec today revealed that some 100,000 Facebook applications have been inadvertently leaking access to member profiles, pictures, chats, and other information to third parties, including advertisers.

Symantec reported the issue to Facebook, which has now removed the offending API that left the door open for this privacy and security gap. The social network now requires developers to adopt the open-source OAuth authorization protocol to shore up app security. But the damage already could have been done, as hundreds of thousands of Facebook apps could have leaked millions of so-called "access tokens" during the years, according to Symantec.

The good news is that these third parties might not have been aware that they could gain access to the information with the tokens, and Facebook updated its developer road map in response. "We raised [this issue with Facebook], and it looks like they fast-forwarded some steps and discontinued use of that API that had the capability of leakage," says Kevin Haley, director at Symantec Security Response.

Access tokens are basically the "spare keys" that let you read or post to your wall, or access a friend's profile or pictures, for example. Most tokens only live for about two hours, and then they expire, so there's a narrow window of abuse.

"By default, most access tokens expire after a short time, however the application can request offline access tokens which allow them to use these tokens until you change your password, even when you aren’t logged in," according to a post by Symantec researchers disclosing the privacy and security issue.

Facebook, meanwhile, says it has investigated the issue, and has found no sign of abuse.

"We appreciate Symantec raising this issue and we worked with them to address it immediately," a Facebook spokesperson said in a statement. "Unfortunately, their resulting report has a few inaccuracies. Specifically, we've conducted a thorough investigation which revealed no evidence of this issue resulting in a user's private information being shared with unauthorized third parties. In addition, this report ignores the contractual obligations of advertisers and developers which prohibit them from obtaining or sharing user information in a way that violates our policies. Finally, the change we announced yesterday on our developer blog removes the outdated API referred to in Symantec's report."

Even so, Congressmen Edward Markey and Joe Barton reportedly have asked Facebook CEO Mark Zuckerberg to explain just how such a security hole was not previously discovered and how the company will be alerting users about it.

"This is an issue with the way the Web works. Applications that are built on top of this technically could inadvertently leak sensitive information if it is stored in the URL. In this case, the access token was being listed in the URL, and when the third-party application displayed an external advertisement, the access token was sent along with the referral URL information," says Nicholas J. Percoco, senior vice president and head of SpiderLabs at Trustwave. "It is important to remember that the end user granted permission for the application to access and, in some cases, make a post to their Facebook account. "Unfortunately, the side effect of this permission was the possibility of the application using advertisement services of another party and inadvertently passing this access permission along to them." Security experts recommend that Facebook users change their passwords.

But if an unauthorized party has a member's active token, then it might not result in massive spam or other obvious abuse -- it likely would be quietly siphoning information from the profile, unbeknown to the user: "If any are abusing it, it's probably to quietly scrape your information and not to make too much noise," says Nitesh Dhanjani, a senior manager at Ernst & Young and a security expert. "

Have a comment on this story? Please click "Add Your Comment" below. If you'd like to contact Dark Reading's editors directly, send us a message.

Kelly Jackson Higgins is the Executive Editor of Dark Reading. She is an award-winning veteran technology and business journalist with more than two decades of experience in reporting and editing for various publications, including Network Computing, Secure Enterprise ... View Full Bio

Comment  | 
Print  | 
More Insights
Newest First  |  Oldest First  |  Threaded View
How to Think Like a Hacker
Dr. Giovanni Vigna, Chief Technology Officer at Lastline,  10/10/2019
7 SMB Security Tips That Will Keep Your Company Safe
Steve Zurier, Contributing Writer,  10/11/2019
Register for Dark Reading Newsletters
White Papers
Cartoon Contest
Write a Caption, Win a Starbucks Card! Click Here
Latest Comment: The old using of sock puppets for Shoulder Surfing technique. 
Current Issue
7 Threats & Disruptive Forces Changing the Face of Cybersecurity
This Dark Reading Tech Digest gives an in-depth look at the biggest emerging threats and disruptive forces that are changing the face of cybersecurity today.
Flash Poll
2019 Online Malware and Threats
2019 Online Malware and Threats
As cyberattacks become more frequent and more sophisticated, enterprise security teams are under unprecedented pressure to respond. Is your organization ready?
Twitter Feed
Dark Reading - Bug Report
Bug Report
Enterprise Vulnerabilities
From DHS/US-CERT's National Vulnerability Database
PUBLISHED: 2019-10-17
Comtech H8 Heights Remote Gateway 2.5.1 devices allow XSS and HTML injection via the Site Name (aka SiteName) field.
PUBLISHED: 2019-10-17
rtl_p2p_noa_ie in drivers/net/wireless/realtek/rtlwifi/ps.c in the Linux kernel through 5.3.6 lacks a certain upper-bound check, leading to a buffer overflow.
PUBLISHED: 2019-10-16
HongCMS 3.0.0 has XSS via the install/index.php servername parameter.
PUBLISHED: 2019-10-16
HongCMS 3.0.0 has XSS via the install/index.php dbname parameter.
PUBLISHED: 2019-10-16
HongCMS 3.0.0 has XSS via the install/index.php dbusername parameter.