Once used to join a machine to the domain, the account becomes the “owner” of the created computer object, automatically receiving extended permissions. Attackers can exploit this to perform Local Administrator Password Solution (LAPS) password disclosure, Resource-Based Constrained Delegation (RBCD) abuse, and Shadow Credentials attacks. Even if administrators restrict read permissions at the container level, default security descriptors still grant the object creator read access, enabling ms-Mcs-AdmPwd attribute extraction.

To mitigate these risks, three critical security measures are required:

1. Set machine account quota to zero – prevents unauthorized computer object creation: Set-ADDomain -Identity test.local -Replace @{ 'ms-DS-MachineAccountQuota' = 0 }
2. Apply deny permissions for LAPS password reading – blocks domain join accounts from accessing sensitive attributes.
3. Deny write permissions to prevent RBCD abuse – restricts domain join accounts from setting dangerous delegation properties.

Microsoft initially declined to issue patches in 2021, leaving enterprises dependent on community guidance until official recommendations were published in August 2025. True protection now requires layered controls—quota restrictions, deny permissions, and ownership reassignment—supported by continuous monitoring rather than one-time configuration hardening.

Impact

• Privilege Escalation
• Unauthorized Gain Access

Remediation

• Review and restrict domain join account privileges to ensure they follow least privilege principles.
• Audit Active Directory permissions to identify and remove excessive rights assigned to domain join accounts.
• Implement machine account quota restrictions to block unauthorized device enrollments.
• Enforce deny permissions on sensitive attributes like LAPS and delegation settings to prevent credential abuse.
• Harden deployment infrastructure by removing stored plaintext credentials from imaging and automation files.
• Use secure authentication methods such as gMSA for deployment operations instead of static passwords.
• Continuously monitor AD event logs for suspicious account creation or modification activities.
• Automate password rotation and secret management to minimize credential reuse risks.
• Apply network segmentation and access controls to protect PXE and deployment servers from internal threats.
• Conduct regular penetration testing and configuration reviews to validate the effectiveness of implemented controls.