On February 10, Microsoft disclosed a dangerous vulnerability in all modern versions of Windows, along with a patch to fix it. Nine days may not seem like a long time, but every day that goes by without a real exploit is great news.
Click here for Microsoft’s advisory and links to the patches)
At the same time, there is an exploit out in the wild that performs a distributed denial-of-service by crashing the attacked system. DDoS attacks are a bad thing, of course, but they aren’t as much of a worry from a mass-attack standpoint. Authors can’t make a worm out of a DDoS attack because if the system crashes, there’s scant opportunity to trick the owner into spreading the worm.
A real worm requires a means of infection and the ability to execute arbitrary code on the infected system. The Microsoft advisory indicates that this is possible with the ASN.1 issue.
There have been allegations that the claim of arbitrary code execution is an exaggeration, however, experts advised me that a code execution worm is merely difficult, but not impossible. Given a large number of vulnerable systems in the world, such a worm could still spread.