Yesterday, Adobe released a Security Advisory in response to a grey hat researcher who published details about a zero day vulnerability in Adobe Shockwave. The researcher from Abysssec described a critical memory corruption vulnerability in the popular multimedia rendering application — and he describe the flaw in very great technical detail. He even posted Proof-of-Concept (PoC) exploit code that can leverage the flaw against Windows XP SP3 computers. In short, if an attacker can entice you to a web site containing specially crafted Flash content, an attacker can leverage this flaw to execute code on your machine with your privileges. Since most Windows users have Local Administrator privileges, attackers can often leverage this sort of flaw to gain complete control of their computers.
Since the Abysssec researcher released details about this flaw without first informing Adobe, they haven’t had time to release a patch yet. In their advisory, they verify that this is a critical vulnerability, but they do not share any workaround that might help. They are working with antivirus vendors to make sure they have signatures for this flaw. In the meantime, I highly recommend you use Firefox with the NoScript extension to help protect yourself from this, and many other web-based flaws. While NoScript won’t always block all web attack, it script blocking capability does help mitigate most of them.
Happily, no one has reported attackers exploiting this flaw in the wild yet. However, the researcher’s PoC is easily weaponizable. So I expect malicious versions in the wild soon. If you use Shockwave, I recommend you use caution browsing. I’ll update you as soon as I know more about Adobe’s fix via the Wire or the LiveSecurity Service. — Corey Nachreiner, CISSP