NGSSoftware Insight Security Research Advisory Name: Windows .NET Server (RC1) and MSDE Systems: Windows .NET Server (RC1) and MSDE 2000 Severity: High Risk Category: Configuration Vendor URL: http://www.microsoft.com/ Author: David Litchfield (david@ngssoftware.com) Advisory URL: http://www.ngssoftware.com/advisories/dotnet-msde.txt Date: 3rd September 2002 Advisory number: #NISR03092002B Introduction ************ Though Microsoft Windows .NET Server is still a release candidate, presently at RC1, NGSSoftware has decided to release this warning as anyone evaluating .NET Server is vulnerable if IIS 6 has been installed. when IIS 6 is installed the Microsoft Desktop Engine (MSDE) is also installed. MSDE is based on SQL Server technology designed to support transactional applications in the background. This version of MSDE is vulnerable to the Name Resolution buffer overflows that allows an attacker without a UserID and password to compromise the server. For more details about these overflows please see http://www.nextgenss.com/advisories/mssql-udp.txt , but to summarise ann attacker can send a single UDP packet to port 1434 on the machine running MSDE and overflow a buffer gaining control of the process' path of execution. Fix Information *************** Customers evaluating .NET Server should apply the following patch: http://www.microsoft.com/technet/treeview/?url=/technet/security/bulletin/MS02-043.asp Whilst http://www.microsoft.com/technet/treeview/?url=/technet/security/bulletin/MS02-039.asp specifically addresses these overflows the former URL includes a fix for this issue and others. A check for this problem has been added to NGSSQUirreL, an SQL Server security management tool, of which more information is available from the NGSSite: http://www.nextgenss.com/.