FAQ
What privileges could be gained by an attacker who successfully exploited the vulnerability? An attacker who successfully exploited this vulnerability could gain domain administrator privileges.
Mitigation
The following are several recommendations to consider for securing certificate templates: 1. Remove Overly Broad Enroll or Autoenroll Permissions Avoid granting overly broad enrollment permissions for certificates. Instead, carefully consider which accounts need permissions, and explicitly deny enrollment rights for users or groups of users that should not be eligible for enrollment. 2. Remove Unused Templates from Certification Authorities Several templates are included as part of the installation of an enterprise CA. If those templates are not required, they should be removed. 3. Secure Templates that Allow You to Specify the Subject in the Request: Implement additional signatures on requests Implement certificate manager approval Implement monitoring of certificates issued by the template More details on securing certificate templates can be found here: Securing PKI: Technical Controls for Securing PKI | Microsoft Learn.
FAQ
What types of certificates are vulnerable to this type of attack? Certificates created using a version 1 certificate template with Source of subject name set to "Supplied in the request" are potentially vulnerable if the template is not secured according to the best practices published in the Securing Certificate Templates section of Securing PKI: Technical Controls for Securing PKI | Microsoft Learn.
FAQ
How do I know if my PKI environment is vulnerable to this type of attack? Check if you have published any certificates created using a version 1 certificate template where the Source of subject name is set to "Supplied in the request" and the Enroll permissions are granted to a broader set of accounts, such as domain users or domain computers. An example is the built-in Web Server template, but it is not vulnerable by default due to its restricted Enroll permissions.