ASREPRoast
Retrieve the Kerberos 5 AS-REP etype 23 hash of users without Kerberos pre-authentication required
You can retrieve the Kerberos 5 AS-REP etype 23 hash of users without Kerberos pre-authentication required if you have a list of users on the domain

Without authentication

The ASREPRoast attack looks for users without Kerberos pre-authentication required. That means that anyone can send an AS_REQ request to the KDC on behalf of any of those users, and receive an AS_REP message. This last kind of message contains a chunk of data encrypted with the original user key, derived from its password. Then, by using this message, the user password could be cracked offline. More detail in Kerberos theory.
1
cme ldap 192.168.0.104 -u harry -p '' --asreproast output.txt
Copied!
Using a wordlist, you can find wordlists of username here
1
cme ldap 192.168.0.104 -u user.txt -p '' --asreproast output.txt
Copied!
Set the password value to '' to perform the test without authentication

With authentication

If you have one valid credential on the domain, you can retrieve all the users and hashs where the Kerberos pre-authentication is not required
1
cme ldap 192.168.0.104 -u harry -p pass --asreproast output.txt
Copied!
Use option kdcHost when the domain name resolution fail
1
cme ldap 192.168.0.104 -u harry -p pass --asreproast output.txt --kdcHost ip_dc
Copied!

Cracking with hashcat

To crack hashes on the file output.txt with hashcat use the following options:
1
hashcat -m18200 output.txt wordlist
Copied!

Example

Forest machine is a good example to test ASREPRoast with CrackMapExec
https://www.hackthebox.eu/home/machines/profile/212
www.hackthebox.eu

Ressources

Kerberos (II): How to attack Kerberos?
Tarlogic Security
AS-REP Roasting
Red Teaming Experiments
AS_REP Roasting
hackndo
​
​
Last modified 1yr ago