Downloads, Hacking Tools, Memory Management, Microsoft, Pass-The-Hash, PowerShell, Priv2Admin, Privesc, Registry, Syscalls, UEFI, Windows

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.

PrivilegeImpactToolExecution pathRemarks
SeAssignPrimaryTokenAdmin3rd 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 Aurélien Chalot for the update. I will try to re-phrase it to something more recipe-like soon.
SeAuditThreat3rd party toolWrite 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.
SeBackupAdmin3rd party tool1. 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.
SeChangeNotifyNonePrivilege held by everyone. Revoking it may make the OS (Windows Server 2019) unbootable.
SeCreateGlobal???
SeCreatePagefileNoneBuilt-in commandsCreate hiberfil.sys, read it offline, look for sensitive data.Requires offline access, which leads to admin rights anyway.
SeCreatePermanent???
SeCreateSymbolicLink???
SeCreateTokenAdmin3rd party toolCreate arbitrary token including local admin rights with NtCreateToken.
SeDebugAdminPowerShellDuplicate the lsass.exe token.Script to be found at FuzzySecurity
SeDelegateSession-
UserImpersonate
???Privilege name broken to make the column narrow.
SeEnableDelegationNoneThe privilege is not used in the Windows OS.
SeImpersonateAdmin3rd party toolTools 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.

SeIncreaseBasePriorityAvailabilityBuilt-in commandsstart /realtime SomeCpuIntensiveApp.exeMay be more interesting on servers.
SeIncreaseQuotaAvailability3rd party toolChange 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.
SeIncreaseWorkingSetNonePrivilege held by everyone. Checked when calling fine-tuning memory management functions.
SeLoadDriverAdmin3rd party tool1. 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
SeLockMemoryAvailability3rd party toolStarve System memory partition by moving pages.PoC published by Walied Assar (@waleedassar)
SeMachineAccountNoneThe privilege is not used in the Windows OS.
SeManageVolumeAdmin3rd party tool1. 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.
SeProfileSingleProcessNoneThe 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.
SeRelabelThreat3rd party toolModification 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.

SeRemoteShutdownAvailabilityBuilt-in commandsshutdown /s /f /m \\server1 /d P:5:19The privilege is verified when shutdown/restart request comes from the network. 127.0.0.1 scenario to be investigated.
SeReserveProcessorNoneIt 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.
SeRestoreAdminPowerShell1. 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.

SeSecurityThreatBuilt-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.

SeShutdownAvailabilityBuilt-in commandsshutdown.exe /s /f /t 1Allows to call most of NtPowerInformation() levels. To be investigated.
SeSyncAgentNoneThe privilege is not used in the Windows OS.
SeSystemEnvironmentUnknown3rd party toolThe 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???
SeSystemtimeThreatBuilt-in commandscmd.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.
SeTakeOwnershipAdminBuilt-in commands1. 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.

SeTcbAdmin3rd party toolManipulate tokens to have local admin rights included.Sample code+exe creating arbitrary tokens to be found at PsBits.
SeTimeZoneMessBuilt-in commandsChange the timezone. tzutil /s "Chatham Islands Standard Time"
SeTrustedCredManAccess???
SeUndockNoneThe 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.
SeUnsolicitedInputNoneThe privilege is not used in the Windows OS.

Credits:

Source : KitPloit – PenTest Tools!

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