Vendors are finally releasing patches today for the TCP vulnerabilities first publicized nearly a year ago that affect a huge range of networking products, including any device running a version of Cisco’s IOS software, and a number of Microsoft server and desktop operating systems. Both Microsoft and Cisco released fixes for the vulnerabilities on Tuesday.

via Microsoft, Cisco Issue Patches for TCP DoS Flaw | threatpost.

This is a Denial of Service issue and not a remote takeover.  Basically somebody can hang your mahcine if they want to whenever they want to.  This has been known since 2005 but mitigating this is going to take more time(in years) for all of hte old, non-supported/updated hardware to be phased out.  This is a minor issue at the worst.