Danger, USB! Questions Raised By CPLINK Zero-Day Vulnerability

Are you taking your USB stick security seriously? That's just one of many questions you ought to be be asking yourself right now.The big security story right now is the zero-day vulnerability in Windows, which can let a program run automatically off a USB stick (and from other places -- for instance, network shares) even if you merely browse to the files on the thumb drive, and even if you have AutoRun and Autoplay turned off.

In other words, viewing a USB stick's directory in Explorer can run a file in the directory without asking permission. Ouch!

The good news is that up-to-date security software can block this behavior by blocking the special files (malicious LNK files), which drive the so-called "CPLINK" exploit.

But the whole problem begs a bigger question: What are you doing about potentially dangerous USB sticks from outside in the first place? And why are you letting uninfected memory sticks from inside get written to outside the network at all?

Shouldn't you keep any unwanted USB sticks out -- not just in case of malware, but in case of any untrustworthy anything?

And shouldn't you protect your own uninfected, important, and trusted keys from any sort of compromise, whether by malware or by data stealing, by any sort of cybercriminal activity?

Shouldn't you be considering device control? Device encryption?

Yes, there's a big story in the media because of the malware problem. But the core problem is deeper: the rogue movement of data and the rogue use of your own USB resources!

Graham Cluley is senior technology consultant at Sophos, and has been working in the computer security field since the early 1990s. When he's not updating his award-winning other blog on the Sophos website, you can find him on Twitter at @gcluley. Special to Dark Reading.