Questions tagged [kerberos]

Kerberos is a network authentication protocol designed to allow nodes, communicating over a non-secure network, to prove their identity to one another in a secure manner.

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Kerberos Attacks Questions

It's amazing how many "Attacks on Kerberos" articles exist out there and almost none really explains the small details. My guess is that usually they assume it's basic knowledge and sometimes, they ...
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Detect Kerberoasting activity

I am working to detect kerberoasting activity and I am referring this link. It states that an account cannot be requesting several different service names within a second or two of each other. What is ...
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How to update authorization information in a KDC dynamically?

I wish to add Kerberos authentication and authorization into a project that has a service server that interacts with a Hadoop cluster that has some users and permissions. As far as I know, the KDC ...
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Web API authentication with Kerberos

We are implementing a web application that uses Kerberos for authentication. In the browser there is no concerns, so it works perfect. Now we need to supply a subset of web application services via ...
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Kerberos Constrained Delegation

I have 4 machines, one machine with Domain Controller, one machine with Analysis Services, one machine with IIS Services, one machine with the Application The goal is to open the application and the ...
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Caching TGT from a browser

I'm playing around with Kerberos SSO. As experimented so far, When I open a web app that is configured with Kerberos, from the browser, it prompts me for the username and credential, once I enter, I'...
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Kerberos with HTTP Resource Server Login

I am having an http (IIS) resource server which uses Kerberos 5 for authentication. Every time I reach the page I need to key in my username and password but if I have done kinit in my machine (...
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Does kerberos support a grace period in password changes?

The principles are programs instead of human. I want to rotate their password regularly, using random generated password, and then deliver the new password to the programs. I have a mechanism to make ...
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Bruteforcing via port 88 on MacOS

Macos has open port 88 by default. Is it possible to check validity of the password via this port from Linux and how? If the vncserver is active, it is possible to know also the username (by ...
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How much time is needed for bruteforce kerberos/ntlm?

My question is simply how much time an attacker needs for full bruteforce on typical complexity password policy given either kerberos ticket/ as req or Ntlm transaction. This depends on the ...
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How to retrieve Kerberos Service tickets?

I am learning Kerberoasting see below are my steps that I am following. Step:1. Attacker will find the SPN's Step:2. After identifying we will request for TGS for that SPN. This is the script for ...
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Use Kerberos Golden Ticket with Metasploit

Having compromised a domain controller during testing, I now wish to create persistent domain admin access. Also, operational security is important for me as I don't want to be logging into netowkr ...
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Questions regarding pass the ticket

In the blackhat talk by Gentikwiki on Mimikatz back in 2014, he mentioned that you can pass the service ticket also, but i am unable to replicate it in a lab. It throws an access denied. Passing the ...
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Kerberos Protocol Centralized Server

If a small company is expanding with various branches across the country, how would the kerberos centralized server be configured? Are the new users assigned new ticket granting servers or are they ...
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Why the need for user ID in ticket AND authenticator (Kerberos)?

I am currently learning about Kerberos. Why the following in Kerberos v4: Client -> Service : Ticket_Service || Authenticator_Client where Ticket_Service: E(K_S, [K_C,S || ID_C || ...]) and ...
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How do I lookup the UID of a domain user?

I'm playing with golden ticket (mimikatz) kerberos::golden /domain:vln2012.local /sid:S-1-5-21-3871786346-2057636518-1625323419 /rc4:8ad36fef31e071eac7ab9d54a093cb54 /user:user1 /id:1109 /groups:500,...
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LDAPS needed when using Kerberos?

In the past two years i built up a small office with more needs every day. At some point i needed a DC with Kerberos. All Server (CentOS besides the DCs) communicate over Kerberos with the DC. Since ...
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Kerberos and brute-force attacks

Suppose that I am the administrator of a system that uses Kerberos and password authentication. How can I make brute-force attacks on user’s passwords by an attacker who can capture network traffic ...
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Exception: krb_error 0 Do not have keys of types listed in default_tkt_enctypes

I am looking for your help with one Exception we are getting while setting up our Kerberos SSO. I will briefly give an overview of our setup and things we tried till now and exception we are getting: ...
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Kerberos composite authentication that reflects user's origin

I'm experimenting with Kerberos and was wondering if some sort of composite authentication that identifies both a user and the origin of the users request was a) possible and b) implemented anywhere....
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In kerberos will a key for a host prinicpal work if the keytab containing the key is stored somewhere inaccessible to that host?

I'm following the instructions here: https://www.freeipa.org/page/Windows_authentication_against_FreeIPA to try to allow a Windows machine to authenticate logins against a FreeIPA server on RHEL. I'...
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What are some scenarios I would use MSFT Certificate Enrollment Web Services?

The Certificate Enrollment Policy Web Service and the Certificate Enrollment Web Service are made for non domain connected machines to retrieve certificates of various kinds. When setting this up, I ...
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How to get Service_key and the corresponding function call interface from the Samba source TGS_REP part

1, My existing configuration environment are as follows: (1), Server_side, Redhat5.5 Enterprise with samba4.0.0 installed, Ip Address: 5.5.5.149; domain name: EXAMPLE.COM; (2), Client_side: windows ...
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Known plain-text attack on Kerberos

This is a form of the Kerberos protocol I have two questions. Why does this protocol give the opportunity of a known plain-text attack because of no authentication of Joe? And how would an attacker ...
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Kerberos Encryption and Decryption

Hacker is able to sniff the traffic between the editor, the KDC and the network scanner during the key exchange. Is he/she able to decrypt the sniffed data key?
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In Kerberos authentication protocol, why is the TGT encrypted using the user's key Ka?

When the user first logs in, he fetches his TGT from the KDC along with the session key. I get why Sa (session key) is encrypted with Ka (user's key). But why is TGT also encrypted with Ka. TGT is ...
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What is possible with a non-administrative users Ticket Granting Ticket and/or NTLM hash?

During a penetration test, if a users NTLM hash or a valid Kerberos TGT is compromised, what attacks are possible if the user is not an administrator on any (in scope) workstations? For instance, it ...
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Why Realm_tgs is needed in Kerberos v5 Protocol? (Step 2)

In msg.2 the AS sends Realm_c, ID_c Ticket_tgs, K_c-tgs, times, N1, Real_tgs, ID_tgs encrypted with E_k_c. I can't understand why Real_tgs is included if AS and TGS are on the same machine.
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How to crack AES-based Kerberos TGS tickets (Kerberoasting)?

All material I can find is related to RC4-based Kerberos TGS tickets, since these are easier to crack to obtain the service account's password. However, I want to attempt to crack AES-based Kerberos ...
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A replay attack was detected (4649) & Exchange Healthmailbox

We received alarms for this in our SIEM today. I believe it is expected and just "noise". The alarm was triggered immediately after Exchange cleared the ThrottlingConfig.log. I know Exchange Server ...
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Mimikatz /rc4 argument for pass-the-ticket?

I'm studying how pass-the-ticket works using Mimikatz, i.e., forged Silver and Golden Kerberos tickets. The command usually takes the form (Golden tickets): kerberos::golden /sid:SID /domain:DOMAIN /...
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686 views

Password reset for AD RODC-specific krbtgt_xxxxx accounts

While there's a lot of information [1], [2], [3] about resetting the password for the regular krbtgt account, but I haven't yet found a clear suggestion about RODC-specific krbtgt_xxxxx accounts. ...