This was sent by our IT support; I need help understanding what is going on? How serious is this issue?
This was the letter:
Microsoft has issued an emergency security update to address a critical vulnerability in all supported versions of Windows. Since Microsoft rarely releases security patches outside of Patch Tuesday, the second Tuesday of each month, were considering this security threat to be quite serious.
The problem is considered critical on Windows 2000, Windows XP and Windows Server 2003, meaning this is a vulnerability that can be exploited through little or no help from the user. Microsoft describes the flaw as "important" on Windows Vista and Windows Server 2008 machines (however, if the User Account Control is disabled on Vista, then it becomes critical just as on XP and 2000).
Here are a few details: the vulnerability lies with Microsoft's implementation of "remote procedure call" (RPC), a communications technology deeply embedded in the Windows operating system that allows a program to execute another process on a remote system. The RPC attack is levied against the Server service, which is present on all Microsoft operating systems, even desktop operating systems. RPC vulnerabilities are extremely dangerous, as they can be used by a computer worm to quickly spread malicious software to machines on a network.
Most computer systems and networks download these patches automatically, however many servers are configured to manually install these patches to eliminate possible problems. These patch installations are typically done by our support personnel on a regular basis. This patch will require us to install it outside of the normal scheduled install time. If this will impact your systems or access we will contact you and let you know.
Its also a good idea to verify any home computers you or your co-workers have are protected. You can verify this by using Internet Explorer, and from the Tools Menu, selecting Windows Update.
In simple and shorter terms; help me understand.