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.


Twitter Pursues Two-Factor Authentication After Password Breach

Live attack compromised up to 250,000 accounts, leading Twitter to reset affected users' passwords.

Twitter is pursuing two-factor authentication to improve log-on security.

That news follows Twitter's Friday disclosure of a security breach affecting an estimated 250,000 of its 250 million users. Following the breach, Twitter reset passwords for all affected users but said its related investigation -- including identifying exactly what data attackers accessed -- remains underway.

"This week, we detected unusual access patterns that led to us identifying unauthorized access attempts to Twitter user data," said Bob Lord, Twitter's director of information security, in a Friday blog post.

So far, however, it's not clear exactly what the attackers may have accessed. "We discovered one live attack and were able to shut it down in process moments later," Lord said. "However, our investigation has thus far indicated that the attackers may have had access to limited user information -- usernames, email addresses, session tokens and encrypted/salted versions of passwords -- for approximately 250,000 users."

[ What is China's role in the recent New York Times and Wall Street Journal hacks? Read NYT, WSJ Hacks Scrutinized By Security Community. ]

To err on the side of caution, Lord said passwords for those 250,000 users had been reset and that they should have received an email from Twitter telling them to create a new password. "As a precautionary security measure, we have reset passwords and revoked session tokens for these accounts," he said. "Your old password will not work when you try to log in to Twitter." Lord also urged users to pay attention to recently issued warnings from the Department of Homeland Security that using any version of the Java browser plug-in should be avoided unless absolutely necessary. But Lord said nothing that explicitly tied the breach of Twitter's system to an exploit of a Java vulnerability.

The ease with which attackers in possession of Twitter users' passwords can gain access to those users' accounts and to all private communications using Twitter appears to have driven company officials to begin pursuing two-factor authentication. This was revealed by a job listing on Twitter's site for a software engineer--product security. Listed in the job description is the responsibility to "design and develop user-facing security features, such as multifactor authentication and fraudulent login detection."

The job listing was spotted Monday by Britain's Guardian newspaper. Twitter didn't immediately respond to an emailed request for comment about whether it planned to add two-factor authentication to the site, or when it might make such a feature available. But Twitter's apparent two-factor authentication plans have already drawn praise. "This is a splendid idea -- I'm looking forward to it. It's something that we've wanted for some time," Graham Cluley, senior technology consultant at Sophos, told the Guardian. "We've often said we would be prepared to pay for it -- Twitter could monetize it by offering it to corporations and branded accounts. It would be pretty attractive."

Twitter's last major user-facing security improvement came in March 2012, when HTTPS became the default option for connecting to the site, thus securing communications between the Twitter site and Twitter users. Two-factor authentication, meanwhile, would add an extra layer of defense to Twitter's log-in processes and help stop attackers who managed to hack into Twitter's systems and steal users' passwords from accessing users' accounts.

Two-factor authentication has long been offered by Google for use with Gmail and other Google Apps. Dropbox, meanwhile, began offering two-factor authentication after suffering an embarrassing password breach. For both Google and Dropbox, users who have enabled two-factor authentication must enter both their password and a unique code -- the second factor -- generated either by an app on their smartphone or sent to their mobile phone in an SMS message.

Until Twitter adopts such a system, its only recourse when attackers hack into its systems and steal users' passwords -- assuming that the company spots the breach -- is to immediately expire those passwords, as Twitter says it has done. Interestingly, however, some affected users have reported that their expired passwords still work when they log into Twitter via the Twitter API, which is used by third-party tools such as Tweetdeck as well as Twitter's own iOS Twitter apps to allow the application to access Twitter.

According to Twitter spokesperson Jim Prosser, the continuing access comes via Twitter's use of the Open Authorization (OAuth) open source standard for authorization. "TweetDeck and other clients use OAuth, so as long as you don't sign out, you don't have to re-input your credential every time you open the app," Prosser told The Register, which first spotted the problem. But Twitter's failing to expire OAuth tokens means that not all users affected by the breach have had their OAuth session tokens likewise expired.

Twitter didn't immediately respond to an emailed request for comment about whether it might expire the OAuth tokens for users affected by the password breach.

This isn't the first seeming glitch in how Twitter handles third-party authentication to its services. Last month, notably, security researcher Cesar Cerrudo reported finding "a simple bypass trick for third-party applications to obtain access to a user's Twitter direct messages." Cerrudo said he made the discovery after finding that a Web application he was testing -- to which he hadn't granted authorization to access his direct messages -- was able to access and display those messages.

Wily attackers are using shape-shifting malware to fool your defenses. Are you ready? Also in the new, all-digital Malware's Next Generation issue of Dark Reading: The shift in hacking requires a new defense mindset. (Free with registration.)

Comment  | 
Print  | 
More Insights
Newest First  |  Oldest First  |  Threaded View
User Rank: Apprentice
2/5/2013 | 6:14:27 AM
re: Twitter Pursues Two-Factor Authentication After Password Breach
why don't they use and external system?n++
Christopher Budd
Christopher Budd,
User Rank: Apprentice
2/4/2013 | 10:00:02 PM
re: Twitter Pursues Two-Factor Authentication After Password Breach
I'm surprised that Twitter has taken this long to look into 2FA. I'm even more surprised we haven't seen a bigger problem like this sooner.

For reference, Yahoo and Facebook also have 2FA schemes. Microsoft doesnt, though they have some mitigations with "Trusted PCs" and limited 2FA on sites like their billing and XBox Points sites.
Sodinokibi Ransomware: Where Attackers' Money Goes
Kelly Sheridan, Staff Editor, Dark Reading,  10/15/2019
Data Privacy Protections for the Most Vulnerable -- Children
Dimitri Sirota, Founder & CEO of BigID,  10/17/2019
Register for Dark Reading Newsletters
White Papers
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: 2019-10-18
In the Linux kernel before 5.3.4, a reference count usage error in the fib6_rule_suppress() function in the fib6 suppression feature of net/ipv6/fib6_rules.c, when handling the FIB_LOOKUP_NOREF flag, can be exploited by a local attacker to corrupt memory, aka CID-ca7a03c41753.
PUBLISHED: 2019-10-18
In xsltCopyText in transform.c in libxslt 1.1.33, a pointer variable isn't reset under certain circumstances. If the relevant memory area happened to be freed and reused in a certain way, a bounds check could fail and memory outside a buffer could be written to, or uninitialized data could be disclo...
PUBLISHED: 2019-10-18
HCL Traveler versions 9.x and earlier are susceptible to cross-site scripting attacks. On the Problem Report page of the Traveler servlet pages, there is a field to specify a file attachment to provide additional problem details. An invalid file name returns an error message that includes the entere...
PUBLISHED: 2019-10-18
In Horner Automation Cscape 9.90 and prior, improper validation of data may cause the system to write outside the intended buffer area, which may allow arbitrary code execution.
PUBLISHED: 2019-10-18
In Horner Automation Cscape 9.90 and prior, an improper input validation vulnerability has been identified that may be exploited by processing files lacking user input validation. This may allow an attacker to access information and remotely execute arbitrary code.