The two critical advisories are unusual in that they don’t touch older versions of Windows or Internet Explorer. The first patches a remote code execution vulnerability that affects Windows 7 through to Windows 8.1, including 8.1 RT. The second, also a remote code execution, is actually an issue in Forefront Protection for Exchange Server (2010).
Given a remote code execution in a perimeter service like Forefront, I’d have to say that this is the highest priority patching issue this month. The second is, not surprisingly, the critical in Windows 7 and later.
The other three issues are all of lower risk and likely lower exploitability, ranging from information disclosure to denial of service and elevation of privilege. Not to be ignored, but should be of slightly less concern than remote critical vulnerabilities.
Author: Ross Barrett, Senior Manager, Security Engineering, Rapid7.