Microsoft recently added a new initiative to its Microsoft Active Protection Program (MAPP), called the Advisory Initiative program, which gives partners up to 96 hours to provide protection for discovered vulnerabilities. Microsoft piloted the program with an advisory release on the Win32K TrueType font parsing engine, related to the Duqu malware (CVE-2011-3402). Sourcefire released its protections for this threat within the first 48 hours, as noted on the MAPP site http://technet.microsoft.com/en-us/security/advisorymapp:
SID: GID 3, SID 20539
Duqu exploits a vulnerability in Windows in the way it parses TrueType fonts and it can create an open tunnel into a user's computer. Then attackers have the freedom to gain full system access and run arbitrary code and modify data, install applications, and, essentially, use the system as the user would. This flaw, for which Microsoft previously issued a workaround, is exploitable across many Windows platforms. Despite this, Microsoft reports that they are currently seeing low customer impact at this time.
More information, as well as other vendors who responded within 48 hours, can be found on the MAPP program web site.