Target Domain Flags for GetNPUsers & GetADUser

Hello Impacket team!

Overview

Recently our team identified a small oddity in GetNPUsers.py && GetADUsers.py where you couldn't ASREP-Roast or query users in other domains. To remedy this, I modified the logic that both scripts use to create the LDAP search scope

Changes

The original code is something like so:

            domainParts = self.__domain.split('.')
            self.baseDN = ''
            for i in domainParts:
                self.baseDN += 'dc=%s,' % i
            # Remove last ','
            self.baseDN = self.baseDN[:-1]

Which essentially retrieves the LDAP search scope from self.__domain (which is directly passed into the init function from the main function's provided credentials). It now checks and sees if the user provided a target domain flag:

    group.add_argument('-targetdomain', action='store',metavar='targetdomain', help='The domain you would like to target in case of a domain trust.')

The full change in the init function now checks if the supplied value is None/Null, if so, it'll then parse from the domain. If not, it'll first prefer the users set target domain through a simple if statement:

        if(self.__targetdomain == None):
            domainParts = self.__domain.split('.')
            self.baseDN = ''
            for i in domainParts:
                self.baseDN += 'dc=%s,' % i
            # Remove last ','
            self.baseDN = self.baseDN[:-1]
        else:
            domainParts = self.__targetdomain.split('.')
            self.baseDN = ''
            for i in domainParts:
                self.baseDN += 'dc=%s,' % i
            # Remove last ','
            self.baseDN = self.baseDN[:-1]

Both of the code is shared within GetNPUsers.py && GetADUsers.py. The only other code change is within GetNPUsers.py within the getTGT function where a similar check (if target domain != None, set this, else, that):

        if self.__targetdomain != None:
            domain = self.__targetdomain.upper()
        else:
            domain = self.__domain.upper()

Testing

This was tested in both a lab environment as well as a production active directory domain to ensure functionality wasn't broken. An example screenshot can be found here: In the above example, the Administrator lives in the NANAISU domain, which has a bidirectional trust with the MSP domain as seen in the following screenshot: Within the MSP domain there is two users, sqlUser and Ronnie. sqlUser has "Do not require Kerberos Pre-Auth" checked to allow for GetNPUsers.py testing. Testing the inverse also works. Users on the MSP domain can query the NANAISU domain:

If there's any questions or concerns, please let me know! I hope this helps!

fortra / impacket