Microsoft plans to issue three fixes in its March security patch rollout, with one deemed "critical" and two labeled "important." Spoofing vulnerabilities will be addressed in the two important security bulletins. Spoofing is the act of masking Internet Protocol addresses to impersonate a sender or another computer. Remote code execution (RCE) exploits -- a repeat problem that Redmond has been patching over the last few years -- will be addressed in the critical item. The critical fix will patch every OS in Microsoft's currently supported repertoire: Windows 2000, XP and Vista, plus Windows Server 2003 and 2008.