Priv2Admin - Exploitation Paths Allowing You To (Mis)Use The Windows Privileges To Elevate Your Rights Within The OS

The idea is to "translate" Windows OS privileges to a path leading to:

  1. administrator,
  2. integrity and/or confidentiality threat,
  3. availability threat,
  4. just a mess.

Privileges are listed and explained at: https://docs.microsoft.com/en-us/windows/win32/secauthz/privilege-constants

If the goal can be achieved multiple ways, the priority is

  1. Using built-in commands
  2. Using PowerShell (only if a working script exists)
  3. Using non-OS tools
  4. Using any other method

You can check your own privileges with whoami /priv. Disabled privileges are as good as enabled ones. The only important thing is if you have the privilege on the list or not.

Note 1: Whenever the attack path ends with a token creation, you can assume the next step is to create new process using such token and then take control over OS.

Note 2:
a. For calling NtQuerySystemInformation()/ZwQuerySystemInformation() directly, you can find required privileges here.
b. For NtSetSystemInformation()/ZwSetSystemInformation() required privileges are listed here here.

Note 3: I am focusing on the OS only. If a privilege works in AD but not in the OS itself, I am describing it as not used in the OS. It would be nice if someone digs deeper into AD-oriented scenarios.

Feel free to contribute and/or discuss presented ideas.

Privilege Impact Tool Execution path Remarks
SeAssignPrimaryToken Admin 3rd party tool "It would allow a user to impersonate tokens and privesc to nt system using tools such as potato.exe, rottenpotato.exe and juicypotato.exe" Thank you AurĂŠlien Chalot for the update. I will try to re-phrase it to something more recipe-like soon.
SeAudit Threat 3rd party tool Write events to the Security event log to fool auditing or to overwrite old events. Writing own events is possible with Authz Report Security Event API.
SeBackup Admin 3rd party tool 1. Backup the HKLM\SAM and HKLM\SYSTEM registry hives
2. Extract the local accounts hashes from the SAM database
3. Pass-the-Hash as a member of the local Administrators group

Alternatively, can be used to read sensitive files.
For more information, refer to the SeBackupPrivilege file.
SeChangeNotify None - - Privilege held by everyone. Revoking it may make the OS (Windows Server 2019) unbootable.
SeCreateGlobal ? ? ?
SeCreatePagefile None Built-in commands Create hiberfil.sys, read it offline, look for sensitive data. Requires offline access, which leads to admin rights anyway.
SeCreatePermanent ? ? ?
SeCreateSymbolicLink ? ? ?
SeCreateToken Admin 3rd party tool Create arbitrary token including local admin rights with NtCreateToken.
SeDebug Admin PowerShell Duplicate the lsass.exe token. Script to be found at FuzzySecurity
? ? ? Privilege name broken to make the column narrow.
SeEnableDelegation None - - The privilege is not used in the Windows OS.
SeImpersonate Admin 3rd party tool Tools from the Potato family (potato.exe, rottenpotato.exe and juicypotato.exe), RogueWinRM, etc. Similarly to SeAssignPrimaryToken, allows by design to create a process under the security context of another user (using a handle to a token of said user).

Multiple tools and techniques may be used to obtain the required token.
SeIncreaseBasePriority Availability Built-in commands start /realtime SomeCpuIntensiveApp.exe May be more interesting on servers.
SeIncreaseQuota Availability 3rd party tool Change cpu, memory, and cache limits to some values making the OS unbootable. - Quotas are not checked in the safe mode, which makes repair relatively easy.
- The same privilege is used for managing registry quotas.
SeIncreaseWorkingSet None - - Privilege held by everyone. Checked when calling fine-tuning memory management functions.
SeLoadDriver Admin 3rd party tool 1. Load buggy kernel driver such as szkg64.sys
2. Exploit the driver vulnerability

Alternatively, the privilege may be used to unload security-related drivers with ftlMC builtin command. i.e.: fltMC sysmondrv
1. The szkg64 vulnerability is listed as CVE-2018-15732
2. The szkg64 exploit code was created by Parvez Anwar
SeLockMemory Availability 3rd party tool Starve System memory partition by moving pages. PoC published by Walied Assar (@waleedassar)
SeMachineAccount None - - The privilege is not used in the Windows OS.
SeManageVolume Admin 3rd party tool 1. Enable the privilege in the token
2. Create handle to \.\C: with SYNCHRONIZE | FILE_TRAVERSE
3. Send the FSCTL_SD_GLOBAL_CHANGE to replace S-1-5-32-544 with S-1-5-32-545
4. Overwrite utilman.exe etc.
FSCTL_SD_GLOBAL_CHANGE can be made with this piece of code.
SeProfileSingleProcess None - - The privilege is checked before changing (and in very limited set of commands, before querying) parameters of Prefetch, SuperFetch, and ReadyBoost. The impact may be adjusted, as the real effect is not known.
SeRelabel Threat 3rd party tool Modification of system files by a legitimate administrator? See: MIC documentation

Integrity labels are infrequently used and work only on top of standard ACLs. Two main scenarios include:
- protection against attacks using exploitable applications such as browsers, PDF readers etc.
- protection of OS files.

Attacks with SeRelabel must obey access rules defined by ACLs, which makes them significantly less useful in practice.
SeRemoteShutdown Availability Built-in commands shutdown /s /f /m \\server1 /d P:5:19 The privilege is verified when shutdown/restart request comes from the network. scenario to be investigated.
SeReserveProcessor None - - It looks like the privilege is no longer used and it appeared only in a couple of versions of winnt.h. You can see it listed i.e. in the source code published by Microsoft here.
SeRestore Admin PowerShell 1. Launch PowerShell/ISE with the SeRestore privilege present.
2. Enable the privilege with Enable-SeRestorePrivilege).
3. Rename utilman.exe to utilman.old
4. Rename cmd.exe to utilman.exe
5. Lock the console and press Win+U
Attack may be detected by some AV software.

Alternative method relies on replacing service binaries stored in "Program Files" using the same privilege.
SeSecurity Threat Built-in commands - Clear Security event log: wevtutil cl Security

- Shrink the Security log to 20MB to make events flushed soon: wevtutil sl Security /ms:0

- Read Security event log to have knowledge about processes, access and actions of other users within the system.

- Knowing what is logged to act under the radar.

- Knowing what is logged to generate large number of events effectively purging old ones without leaving obvious evidence of cleaning.
SeShutdown Availability Built-in commands shutdown.exe /s /f /t 1 Allows to call most of NtPowerInformation() levels. To be investigated.
SeSyncAgent None - - The privilege is not used in the Windows OS.
SeSystemEnvironment Unknown 3rd party tool The privilege permits to use NtSetSystemEnvironmentValue, NtModifyDriverEntry and some other syscalls to manipulate UEFI variables. - Firmware environment variables were commonly used on non-Intel platforms in the past, and now slowly return to UEFI world.
- The area is highly undocumented.
- The potential may be huge (i.e. breaking Secure Boot) but raising the impact level requires at least PoC.
SeSystemProfile ? ? ?
SeSystemtime Threat Built-in commands cmd.exe /c date 01-01-01
cmd.exe /c time 00:00
The privilege allows to change the system time, potentially leading to audit trail integrity issues, as events will be stored with wrong date/time.
- Be careful with date/time formats. Use always-safe values if not sure.
- Sometimes the name of the privilege uses uppercase "T" and is referred as SeSystemTime.
SeTakeOwnership Admin Built-in commands 1. takeown.exe /f "%windir%\system32"
2. icalcs.exe "%windir%\system32" /grant "%username%":F
3. Rename cmd.exe to utilman.exe
4. Lock the console and press Win+U
Attack may be detected by some AV software.

Alternative method relies on replacing service binaries stored in "Program Files" using the same privilege.
SeTcb Admin 3rd party tool Manipulate tokens to have local admin rights included. Sample code+exe creating arbitrary tokens to be found at PsBits.
SeTimeZone Mess Built-in commands Change the timezone. tzutil /s "Chatham Islands Standard Time"
SeTrustedCredManAccess ? ? ?
SeUndock None - - The privilege is enabled when undocking, but never observed it checked to grant/deny access. In practice it means it is actually unused and cannot lead to any escalation.
SeUnsolicitedInput None - - The privilege is not used in the Windows OS.


Disqus Comments