Microsoft's Christopher Rudd published a post over at MSRC that details the recently posted Microsoft Security Advisory 972890, which discusses new, limited attacks against a Microsoft Video ActiveX Control affecting Windows XP and Windows Server 2003 users.
"Specifically, we’re aware of a code execution vulnerability within this control that can enable an attacker to run code as the logged-on user if they browse to a malicious site," writes Rudd. "We have an investigation into this issue under way as part of our Software Security Incident Response Process (SSIRP) and are working to develop a security update to address the issue," he added.
It's unusual for Microsoft to highlight a vulnerability without already having a fix for it. The company yesterday announced that it was investigating a privately reported vulnerability in Microsoft Video ActiveX Control. According to the announcement, an attacker who managed to successfully exploit the vulnerability could gain the same user rights as the local user. That said, Microsoft does have an "in the meantime," band aid-type fix for the problem.
"In the meantime, our investigation has shown that there are no by-design uses for this ActiveX Control within Internet Explorer. Therefore, we’re recommending that all customers go ahead and implement the workaround outlined in the Security Advisory: setting all killbits associated with this particular control. While Windows Vista and Windows Server 2008 customers are not affected by this vulnerability, we are recommending that they also set these killbits as a defense-in-depth measure. Once that killbit is set, any attempt by malicious websites to exploit the vulnerability would not succeed."
Check out Microsoft's security advisory for more information.