News

Microsoft Highlights Network Quarantine Feature in Wake of Attacks

• By Scott Bekker
• August 26, 2003

In the wake of one of the most active weeks for computer worms yet, Microsoft is calling attention to a little-touted new feature of Windows Server 2003 that helps administrators ensure that remote users adhere to company security policies.

The new feature in Windows Server 2003 is called Network Access Quarantine Control, and it essentially puts remote access systems that log into a private network into a quarantine with limited access to the network until an administrator-supplied script can validate that the client system meets the organization's security policies.

Network Access Quarantine Control is not intended as a security measure to keep out attackers who have stolen company credentials. Instead it is intended as a fail-safe to ensure that legitimate users are in compliance with company policies regarding firewalls, anti-virus software, service packs, recent hotfixes and password-protected screensavers.

In the last few days, Microsoft posted a link to a 31-page white paper originally published in late March about Network Access Quarantine on its main TechNet Security page. The white paper can be found here.

Recent obvious benefits of having a Network Access Quarantine policy in place would have been to check systems for enabled firewalls, the MS03-026 patch that blocked the DCOM RPC hole that MSBlast exploited or recent anti-virus signatures protecting against Sobig.F.

"Despite the efforts made within organizations to ensure that computers used internally comply with network policy, those used from employee’s homes for remote access can still present significant risk to the network," Microsoft noted in the white paper.

Microsoft CIO Rick Devenuti discussed Microsoft's internal deployment of the feature on pre-release versions of Windows Server 2003 at the MEC 2002 show last October.