Five of the bulletins address critical vulnerabilties, while two provide fixes for less severe flaws. Among the critical flaws disclosed Tuesday are two that exist on the server side.

One is a vulnerability in the Windows Server Service that could allow hackers to remotely execute code on compromised systems. The other critical server flaw involves the Window Dynamic Host Configuration Protocol Client Service. It, too, could result in remote code execution, according to Microsoft.

"DHCP is a communication protocol that allows administrators to centrally manage and automate the assignment of Internet Protocol (IP) addresses in an organization's network," security vendor Symantec Corp. said in an advisory after the updates were announced.

"Therefore, one compromised system could affect other systems connected to it on the same physical network," the advisory said, adding that users of Windows 2000, Windows XP and Windows Server 2003 may be affected by the flaw.

Meanwhile, the updates for client-side vulnerabilities included one that addresses several vulnerabilties in Microsoft Excel and another that fixes two flaws in Microsoft Office. The third critical client-side update details fixes for two holes in Microsoft Office Filter that could allow attackers to remote-compromise vulnerable systems.