The four updates - all critical - concentrates on Microsoft Office and addresses 12 distinct vulnerabilities. The most pressing of these (MS08-014) covers patches for Excel against vulnerabilities that have become the focus of recent hacker attacks. Updates to all supported versions of Outlook also merit close attention.

The other two advisories cover vulnerabilities in Microsoft Office and Microsoft Office Web Components.

"Because all four of the patches affect Microsoft Office, these patches cannot be ignored or delayed. The broad install base of Microsoft Office makes Office vulnerabilities an enticing target for hackers and cyber criminals," said Alan Bentley, VP in EMEA of patching specialist Lumension.

Bentley added that updating vulnerable Outlook installations ought to be a priority for sys admins. The update to Outlook covers a vulnerability in parsing of "mailto:" URIs that allows malware to be injected onto targeted systems.

"Microsoft Outlook is the dominant email client in use today, and email is also one of the most common attack vehicles used by hackers against organisations. This makes MS08-015 a critical, remote-code-execution vulnerability which affects virtually all versions of Outlook, the biggest priority for IT administrators this Patch Tuesday," he added.

The summary of the Microsoft March patch batch can be found here.

The SANS Institute's Internet Storm Centre (ISC) has published a graphical overview with easy to read colour chart. Click here to view the summary. ISC states that only the Excel bugs have become the target of hacking attack, making them the highest patching priority.

Symantec, by contrast, reckons the advisory to Microsoft Office Web Components is potentially the worst of the bunch.

Given this information, our recommendation is to apply all four critical updates sooner rather than later.