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.
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
@ -9,18 +8,16 @@ Active Directory Certificate Services (AD CS) is a Microsoft Windows server role
* 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.
* 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.
* 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
@ -30,12 +27,12 @@ Active Directory Certificate Services (AD CS) is a Microsoft Windows server role
* 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)
* [PKINIT] Client Authentication, Smart Card Logon, Any Purpose, or No EKU (Extended/Enhanced Key Usage)
**Exploitation**
* Use [Certify.exe](https://github.com/GhostPack/Certify) to see if there are any vulnerable templates
```ps1
Certify.exe find /vulnerable
Certify.exe find /vulnerable /currentuser
@ -46,18 +43,24 @@ Active Directory Certificate Services (AD CS) is a Microsoft Windows server role
* Use Certify, [Certi](https://github.com/eloypgz/certi) or [Certipy](https://github.com/ly4k/Certipy) to request a Certificate and add an alternative name (user to impersonate)
```ps1
# request certificates for the machine account by executing Certify with the "/machine" argument from an elevated command prompt.
@ -66,7 +69,6 @@ Active Directory Certificate Services (AD CS) is a Microsoft Windows server role
**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**
@ -76,45 +78,53 @@ Active Directory Certificate Services (AD CS) is a Microsoft Windows server role
> 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.
> 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](https://github.com/fortalice/modifyCertTemplate)
```ps1
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
* 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
## 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.
> 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](https://github.com/GhostPack/Certify) to check for **UserSpecifiedSAN** flag state which refers to the `EDITF_ATTRIBUTESUBJECTALTNAME2` flag.
```ps1
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
> 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.
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.
<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)
```ps1
certipy shadow auto -username John@corp.local -p Passw0rd -account Jane
```
* Change the **userPrincipalName** of Jane to be Administrator. :warning: leave the `@corp.local` part
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.
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
```ps1
certutil -addstore -user my <CAcertificatefile>
```
* Associated with the private key in the YubiHSM2 device
```ps1
certutil -csp "YubiHSM Key Storage Provider" -repairstore -user my <CACommonName>
```
* 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.
@ -403,27 +433,32 @@ Members : {}
**Exploitation**:
* Request a certificate for the vulnerable template
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](https://msrc.microsoft.com/update-guide/vulnerability/CVE-2024-49019) for more information.
**Requirements**
@ -443,7 +478,6 @@ If there is a conflict between an Application Policy and an EKU, then Microsoft
> "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](https://github.com/ly4k/Certipy/pull/228), we can add the `Client Authentication` EKU to `WebServer`. Anybody with the `Enroll` permission on this template can now compromise the domain.
> 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.
Found Storage Account - redacted.blob.core.windows.net
```
## List and download blobs
Visiting `https://<storage-name>.blob.core.windows.net/<storage-container>?restype=container&comp=list` provides a JSON file containing a complete list of the Azure Blobs.
Use [sysinternals/procmon](https://learn.microsoft.com/fr-fr/sysinternals/downloads/procmon) to find `RegOpenKey` with the status `NAME NOT FOUND`. The process `explorer.exe` is a good target, as it will spawn your payload every time it is run.
Allow any arbitrary non-administrative user to have full SYSTEM permissions on a machine persistently by feeding an overly permissive ACL to the service control manager with sdset.
Then you need to wait for a reboot for the service to automatically start and grant the user with elevated privilege or any persistence mechanism you specified in the `binPath`.
### Scheduled Tasks Elevated
Scheduled Task to run as SYSTEM, everyday at 9am or on a specific day.
### Windows Management Instrumentation Event Subscription
> An adversary can use Windows Management Instrumentation (WMI) to install event filters, providers, consumers, and bindings that execute code when a defined event occurs. Adversaries may use the capabilities of WMI to subscribe to an event and execute arbitrary code when that event occurs, providing persistence on a system.
* **__EventFilter**: Trigger (new process, failed logon etc.)
* [Beware of the Shadowbunny - Using virtual machines to persist and evade detections - Sep 23, 2020 - wunderwuzzi](https://embracethered.com/blog/posts/2020/shadowbunny-virtual-machine-red-teaming-technique/)
* [Persistence via WMI Event Subscription - Elastic Security Solution](https://www.elastic.co/guide/en/security/current/persistence-via-wmi-event-subscription.html)
* [PrivEsc: Abusing the Service Control Manager for Stealthy & Persistent LPE - 0xv1n - 2023-02-27](https://0xv1n.github.io/posts/scmanager/)
* [Sc sdset - Microsoft - 08/31/2016](https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-r2-and-2012/cc742037(v=ws.11))
* [Sc sdset - Microsoft - 08/31/2016](https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-server-2012-r2-and-2012/cc742037(v=ws.11))
* [Hijack the TypeLib. New COM persistence technique - CICADA8 - October 22, 2024](https://cicada-8.medium.com/hijack-the-typelib-new-com-persistence-technique-32ae1d284661)
Swissky