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Kerberos
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Kerberos

Kerberos is AD's auth protocol. Attackers enumerate users, SPNs, and KDCs, then exploit via AS-REP roasting, Kerberoasting, ticket forging, delegation abuse, and ccache reuse for lateral movement

:88 9 guides 4 phases
1 min read Updated: Jul 14, 2026

What is Kerberos?

Kerberos is an authentication protocol used in Active Directory environments.

Common security issues

  • Kerberoasting (ticket cracking).

  • AS-REP roasting.

  • Weak service account passwords.

  • Ticket reuse attacks.

Default ports

  • 88

Enumeration

Valid users, SPNs, AS-REP targets, realm and KDC discovery guides

4

Kerberos SPN enumeration

Enumerate Service Principal Names (SPNs) via Kerberos to identify service accounts, enabling targeted Kerberoasting attacks against AD environments.

Jan 4, 2026 • 4 min read

Vulnerability Discovery

Find AS-REP roastable and Kerberoastable accounts via key tools

2

Kerberoastable Service Accounts

Identify service accounts with SPNs vulnerable to Kerberoasting by extracting and cracking TGS tickets offline to compromise Active Directory credentials.

May 15, 2026 • 4 min read

Kerberos Pre-Authentication Not Required

Identifies accounts with DONT_REQUIRE_PREAUTH set, enabling AS-REP roasting attacks to capture and offline-crack Kerberos hashes without credentials.

May 15, 2026 • 3 min read

Exploitation

Kerberos attacks: roasting, ticket forging, and delegation abuse

2

Lateral Movement

Reuse ccache files and keytabs on Linux to move laterally in AD

1
Kerberos Ticket Reuse from Linux

Kerberos Ticket Reuse from Linux

Exploiting cached Kerberos tickets on Linux via ccache files and keytabs to authenticate as other users and move laterally across AD environments.

Mar 16, 2026 • 4 min read