Feeds

Facebook denies malware risk from message bug

Fixes security bypass flaw anyway

Beginner's guide to SSL certificates

Facebook has fixed a flaw that may have allowed users to attach executables to messages sent to other punters on the social network.

Security blogger Nathan Power notified Facebook after finding the bug, which involved fiddling with messages sent between users who were not necessarily contacts. Facebook normally blocks the exchange of executable files - but Power discovered that by adding an extra space to the end of a filename, it was possible to get around these restrictions, as he explains in a blog post here.

These executable files could very well be laced with malware. Users can get infected if they are tricked into opening the malicious program on a vulnerable machine, something the bug (by itself) doesn't do. Emails with malicious attachments have proved to be an incredibly successful attack vector for years so seeing this getting replayed in the venue of social networking gives El Reg the fear.

Facebook said last week that a fix was unnecessary before deciding to modify its systems this week after successfully reproducing the "undesirable behaviour" reported by Power in late September.

In a statement, Facebook said: "We were originally unsuccessful in reproducing the behaviour described by the reporter, as this behaviour does not occur for all browser and operating system combinations. Upon further investigation, we have determined which scenarios were behaving undesirably and have pushed a fix to ensure a consistent attachment experience across browsers."

Despite the tweak, Facebook continues to insist that its users were never at risk. It said the social network has multiple layers of security to protect people from malicious files. "Facebook Messages does not rely solely on searching the plain-text of the file name to detect potentially malicious files but has antivirus protection that scans every message for malware and malicious links," it said.

Facebook uses anti-malware technology from Websense to carry out this screening of binaries. ®

Protecting users from Firesheep and other Sidejacking attacks with SSL

More from The Register

next story
Spies would need SUPER POWERS to tap undersea cables
Why mess with armoured 10kV cables when land-based, and legal, snoop tools are easier?
Early result from Scots indyref vote? NAW, Jimmy - it's a SCAM
Anyone claiming to know before tomorrow is telling porkies
TOR users become FBI's No.1 hacking target after legal power grab
Be afeared, me hearties, these scoundrels be spying our signals
Jihadi terrorists DIDN'T encrypt their comms 'cos of Snowden leaks
Intel bods' analysis concludes 'no significant change' after whistle was blown
Home Depot: 56 million bank cards pwned by malware in our tills
That's about 50 per cent bigger than the Target tills mega-hack
Hackers pop Brazil newspaper to root home routers
Step One: try default passwords. Step Two: Repeat Step One until success
China hacked US Army transport orgs TWENTY TIMES in ONE YEAR
FBI et al knew of nine hacks - but didn't tell TRANSCOM
Microsoft to patch ASP.NET mess even if you don't
We know what's good for you, because we made the mess says Redmond
NORKS ban Wi-Fi and satellite internet at embassies
Crackdown on tardy diplomatic sysadmins providing accidental unfiltered internet access
prev story

Whitepapers

Providing a secure and efficient Helpdesk
A single remote control platform for user support is be key to providing an efficient helpdesk. Retain full control over the way in which screen and keystroke data is transmitted.
WIN a very cool portable ZX Spectrum
Win a one-off portable Spectrum built by legendary hardware hacker Ben Heck
Saudi Petroleum chooses Tegile storage solution
A storage solution that addresses company growth and performance for business-critical applications of caseware archive and search along with other key operational systems.
Protecting users from Firesheep and other Sidejacking attacks with SSL
Discussing the vulnerabilities inherent in Wi-Fi networks, and how using TLS/SSL for your entire site will assure security.
Security for virtualized datacentres
Legacy security solutions are inefficient due to the architectural differences between physical and virtual environments.