The Negotiate Security Software Provider (SSP) interface in Windows 2000, Windows XP, and Windows Server 2003, allows remote attackers to cause a denial of service (crash from null dereference) or execute arbitrary code via a crafted SPNEGO NegTokenInit request during authentication protocol selection.

Microsoft Exchange 2003 and Outlook Web Access (OWA), when configured to use NTLM authentication, does not properly reuse HTTP connections, which can cause OWA users to view mailboxes of other users when Kerberos has been disabled as an authentication method for IIS 6.0, e.g. when SharePoint Services 2.0 is installed.