The AdjustTokenPrivileges function enables or disables privileges in the specified access token (An access token contains the security information for a logon session. The system creates an access token when a user logs on, and every process executed on behalf of the user has a copy of the token).
Malware that performs process injection often calls this function to gain additional permissions.
Enabling or disabling privileges in an access token requires TOKEN_ADJUST_PRIVILEGES access.
BOOL WINAPI AdjustTokenPrivileges( _In_ HANDLE TokenHandle, _In_ BOOL DisableAllPrivileges, _In_opt_ PTOKEN_PRIVILEGES NewState, _In_ DWORD BufferLength, _Out_opt_ PTOKEN_PRIVILEGES PreviousState, _Out_opt_ PDWORD ReturnLength );
- TokenHandle [in]
- A handle to the access token that contains the privileges to be modified. The handle must have TOKEN_ADJUST_PRIVILEGES access to the token. If the PreviousState parameter is not NULL, the handle must also have TOKEN_QUERY access.
- DisableAllPrivileges [in]
- Specifies whether the function disables all of the token's privileges. If this value is TRUE, the function disables all privileges and ignores the NewState parameter. If it is FALSE, the function modifies privileges based on the information pointed to by the NewState parameter.
- NewState [in, optional]
- A pointer to a TOKEN_PRIVILEGES structure that specifies an array of privileges and their attributes. If the DisableAllPrivileges parameter is FALSE, the AdjustTokenPrivileges function enables, disables, or removes these privileges for the token. The following table describes the action taken by the AdjustTokenPrivileges function, based on the privilege attribute.
Value Meaning SE_PRIVILEGE_ENABLED The function enables the privilege. SE_PRIVILEGE_REMOVED
The privilege is removed from the list of privileges in the token. The other privileges in the list are reordered to remain contiguous.
SE_PRIVILEGE_REMOVED supersedes SE_PRIVILEGE_ENABLED.
Because the privilege has been removed from the token, attempts to reenable the privilege result in the warning ERROR_NOT_ALL_ASSIGNED as if the privilege had never existed.
Attempting to remove a privilege that does not exist in the token results in ERROR_NOT_ALL_ASSIGNED being returned.
Privilege checks for removed privileges result in STATUS_PRIVILEGE_NOT_HELD. Failed privilege check auditing occurs as normal.
The removal of the privilege is irreversible, so the name of the removed privilege is not included in the PreviousState parameter after a call to AdjustTokenPrivileges.
Windows XP with SP1: The function cannot remove privileges. This value is not supported.
None The function disables the privilege.
- If DisableAllPrivileges is TRUE, the function ignores this parameter.
- BufferLength [in]
- Specifies the size, in bytes, of the buffer pointed to by the PreviousState parameter. This parameter can be zero if the PreviousState parameter is NULL.
- PreviousState [out, optional]
- A pointer to a buffer that the function fills with a TOKEN_PRIVILEGES structure that contains the previous state of any privileges that the function modifies. That is, if a privilege has been modified by this function, the privilege and its previous state are contained in the TOKEN_PRIVILEGES structure referenced by PreviousState. If the PrivilegeCount member of TOKEN_PRIVILEGES is zero, then no privileges have been changed by this function. This parameter can be NULL.
- If you specify a buffer that is too small to receive the complete list of modified privileges, the function fails and does not adjust any privileges. In this case, the function sets the variable pointed to by the ReturnLength parameter to the number of bytes required to hold the complete list of modified privileges.
- ReturnLength [out, optional]
- A pointer to a variable that receives the required size, in bytes, of the buffer pointed to by the PreviousState parameter. This parameter can be NULL if PreviousState is NULL.
If the function succeeds, the return value is nonzero. To determine whether the function adjusted all of the specified privileges, call GetLastError, which returns one of the following values when the function succeeds:
|ERROR_SUCCESS||The function adjusted all specified privileges.|
|ERROR_NOT_ALL_ASSIGNED||The token does not have one or more of the privileges specified in the NewState parameter. The function may succeed with this error value even if no privileges were adjusted. The PreviousState parameter indicates the privileges that were adjusted.|
If the function fails, the return value is zero. To get extended error information, call GetLastError.