Rule:--Sid:7294--Summary:This event is generated when an attempt is made to exploit a known vulnerability in Microsoft systems using the Microsoft Windows Server Service. In particular this rule generates an event when an attempt is made to exploit the function "NetrPathCanonicalize".--Impact:Serious. Remote execution of code of the attackers choosing is possible.--Detailed Information:The Microsoft Windows Server Service is used to provide RPC, named pipe, file and printing support services on a network.The Server Service is prone to a buffer overflow vulnerability that may allow an attacker to take complete control of the target host. Insufficient checks are made on user supplied input to calls made to the NetrPathCanonicalize function. This may allow an attacker to excute code of their choosing with system level privileges on an affected host.--Affected Systems:Microsoft Windows Server 2003 SP1 and priorMicrosoft Windows XP SP2Microsoft Windows XP SP1 and priorMicrosoft Windows 2000 SP4 and priorMicrosoft Windows XP Professional--Attack Scenarios:An attacker can supply extra data in a malformed message to the server service to cause the overflow condition to occur. --Ease of Attack:Simple.--False Positives:None known.--False Negatives:None known.--Corrective Action:Apply the appropriate vendor supplied patches.Disallow access to services from untrusted sources.Use a packet filtering firewall to disallow access to ports 139 and 445 from sources external to the protected network.--Contributors:Sourcefire Vulnerability Research TeamBrian Caswell <bmc@sourcefire.com>Nigel Houghton <nigel.houghton@sourcefire.com>--Additional References:--