1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
|
/* SPDX-License-Identifier: GPL-2.0
*
* Copyright (C) 2018-2021 WireGuard LLC. All Rights Reserved.
*/
#include "elevate.h"
#include "logger.h"
#include <Windows.h>
#include <TlHelp32.h>
static _Return_type_success_(return != FALSE) BOOL ElevateToSystem(void)
{
HANDLE CurrentProcessToken, ThreadToken, ProcessSnapshot, WinlogonProcess, WinlogonToken, DuplicatedToken;
PROCESSENTRY32W ProcessEntry = { .dwSize = sizeof(PROCESSENTRY32W) };
BOOL Ret;
DWORD LastError = ERROR_SUCCESS;
TOKEN_PRIVILEGES Privileges = { .PrivilegeCount = 1, .Privileges = { { .Attributes = SE_PRIVILEGE_ENABLED } } };
CHAR LocalSystemSid[MAX_SID_SIZE];
DWORD RequiredBytes = sizeof(LocalSystemSid);
struct
{
TOKEN_USER MaybeLocalSystem;
CHAR LargeEnoughForLocalSystem[MAX_SID_SIZE];
} TokenUserBuffer;
Ret = CreateWellKnownSid(WinLocalSystemSid, NULL, &LocalSystemSid, &RequiredBytes);
if (!Ret)
{
LastError = LOG_LAST_ERROR(L"Failed to create SID");
goto cleanup;
}
Ret = OpenProcessToken(GetCurrentProcess(), TOKEN_QUERY, &CurrentProcessToken);
if (!Ret)
{
LastError = LOG_LAST_ERROR(L"Failed to open process token");
goto cleanup;
}
Ret =
GetTokenInformation(CurrentProcessToken, TokenUser, &TokenUserBuffer, sizeof(TokenUserBuffer), &RequiredBytes);
LastError = GetLastError();
CloseHandle(CurrentProcessToken);
if (!Ret)
{
LOG_ERROR(LastError, L"Failed to get token information");
goto cleanup;
}
if (EqualSid(TokenUserBuffer.MaybeLocalSystem.User.Sid, LocalSystemSid))
return ImpersonateSelf(SecurityImpersonation);
Ret = LookupPrivilegeValueW(NULL, SE_DEBUG_NAME, &Privileges.Privileges[0].Luid);
if (!Ret)
{
LastError = LOG_LAST_ERROR(L"Failed to lookup privilege value");
goto cleanup;
}
ProcessSnapshot = CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0);
if (ProcessSnapshot == INVALID_HANDLE_VALUE)
{
LastError = LOG_LAST_ERROR(L"Failed to create toolhelp snapshot");
goto cleanup;
}
for (Ret = Process32FirstW(ProcessSnapshot, &ProcessEntry); Ret;
Ret = Process32NextW(ProcessSnapshot, &ProcessEntry))
{
if (_wcsicmp(ProcessEntry.szExeFile, L"winlogon.exe"))
continue;
RevertToSelf();
Ret = ImpersonateSelf(SecurityImpersonation);
if (!Ret)
{
LastError = GetLastError();
continue;
}
Ret = OpenThreadToken(GetCurrentThread(), TOKEN_ADJUST_PRIVILEGES, FALSE, &ThreadToken);
if (!Ret)
{
LastError = GetLastError();
continue;
}
Ret = AdjustTokenPrivileges(ThreadToken, FALSE, &Privileges, 0, NULL, NULL);
LastError = GetLastError();
CloseHandle(ThreadToken);
if (!Ret)
continue;
WinlogonProcess = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, ProcessEntry.th32ProcessID);
if (!WinlogonProcess)
{
LastError = GetLastError();
continue;
}
Ret = OpenProcessToken(WinlogonProcess, TOKEN_IMPERSONATE | TOKEN_DUPLICATE, &WinlogonToken);
LastError = GetLastError();
CloseHandle(WinlogonProcess);
if (!Ret)
continue;
Ret = DuplicateToken(WinlogonToken, SecurityImpersonation, &DuplicatedToken);
LastError = GetLastError();
CloseHandle(WinlogonToken);
if (!Ret)
continue;
if (!GetTokenInformation(DuplicatedToken, TokenUser, &TokenUserBuffer, sizeof(TokenUserBuffer), &RequiredBytes))
goto next;
if (!EqualSid(TokenUserBuffer.MaybeLocalSystem.User.Sid, LocalSystemSid))
{
SetLastError(ERROR_ACCESS_DENIED);
goto next;
}
if (!SetThreadToken(NULL, DuplicatedToken))
goto next;
CloseHandle(DuplicatedToken);
CloseHandle(ProcessSnapshot);
return TRUE;
next:
LastError = GetLastError();
CloseHandle(DuplicatedToken);
}
RevertToSelf();
CloseHandle(ProcessSnapshot);
cleanup:
SetLastError(LastError);
return FALSE;
}
_Return_type_success_(return != FALSE) BOOL ImpersonateService(_In_z_ WCHAR *ServiceName, _In_ HANDLE *OriginalToken)
{
HANDLE ThreadToken, ServiceProcess, ServiceToken, DuplicatedToken;
SC_HANDLE Scm, ServiceHandle;
DWORD LastError = ERROR_SUCCESS;
TOKEN_PRIVILEGES Privileges = { .PrivilegeCount = 1, .Privileges = { { .Attributes = SE_PRIVILEGE_ENABLED } } };
SERVICE_STATUS_PROCESS ServiceStatus;
DWORD RequiredBytes;
BOOL Ret = FALSE;
*OriginalToken = NULL;
if (!OpenThreadToken(GetCurrentThread(), TOKEN_IMPERSONATE, FALSE, OriginalToken) &&
GetLastError() != ERROR_NO_TOKEN)
return FALSE;
if (!ElevateToSystem())
goto cleanup;
if (!LookupPrivilegeValueW(NULL, SE_DEBUG_NAME, &Privileges.Privileges[0].Luid))
{
LastError = LOG_LAST_ERROR(L"Failed to lookup privilege value");
goto cleanup;
}
if (!OpenThreadToken(GetCurrentThread(), TOKEN_ADJUST_PRIVILEGES, FALSE, &ThreadToken))
{
LastError = LOG_LAST_ERROR(L"Failed to open thread token");
goto cleanup;
}
if (!AdjustTokenPrivileges(ThreadToken, FALSE, &Privileges, 0, NULL, NULL))
{
LastError = LOG_LAST_ERROR(L"Failed to enable SE_DEBUG_NAME");
goto cleanupThreadToken;
}
Scm = OpenSCManagerW(NULL, NULL, SC_MANAGER_CONNECT);
if (!Scm)
{
LastError = LOG_LAST_ERROR(L"Failed to open SCM");
goto cleanupThreadToken;
}
ServiceHandle = OpenServiceW(Scm, ServiceName, SERVICE_START | SERVICE_QUERY_STATUS);
if (!ServiceHandle)
{
LastError = LOG_LAST_ERROR(L"Failed to open service %s", ServiceName);
goto cleanupScm;
}
if (!StartServiceW(ServiceHandle, 0, NULL) && GetLastError() != ERROR_SERVICE_ALREADY_RUNNING)
{
LastError = LOG_LAST_ERROR(L"Failed to start service %s", ServiceName);
goto cleanupService;
}
for (int i = 0; i < 1000; ++i)
{
if (!QueryServiceStatusEx(
ServiceHandle, SC_STATUS_PROCESS_INFO, (BYTE *)&ServiceStatus, sizeof(ServiceStatus), &RequiredBytes))
{
LastError = LOG_LAST_ERROR(L"Failed to query service %s", ServiceName);
goto cleanupService;
}
if (ServiceStatus.dwProcessId)
break;
if (i != 999)
Sleep(4);
}
ServiceProcess = OpenProcess(PROCESS_QUERY_INFORMATION, FALSE, ServiceStatus.dwProcessId);
if (!ServiceProcess)
{
LastError = LOG_LAST_ERROR(L"Failed to open service %s process %u", ServiceName, ServiceStatus.dwProcessId);
goto cleanupService;
}
if (!OpenProcessToken(ServiceProcess, TOKEN_IMPERSONATE | TOKEN_DUPLICATE, &ServiceToken))
{
LastError =
LOG_LAST_ERROR(L"Failed to open token of service %s process %u", ServiceName, ServiceStatus.dwProcessId);
goto cleanupServiceProcess;
}
if (!DuplicateToken(ServiceToken, SecurityImpersonation, &DuplicatedToken))
{
LastError = LOG_LAST_ERROR(
L"Failed to duplicate token of service %s process %u", ServiceName, ServiceStatus.dwProcessId);
goto cleanupServiceToken;
}
if (!SetThreadToken(NULL, DuplicatedToken))
{
LastError = LOG_LAST_ERROR(
L"Failed to set thread token to service %s process %u token", ServiceName, ServiceStatus.dwProcessId);
goto cleanupDuplicatedToken;
}
Ret = TRUE;
cleanupDuplicatedToken:
CloseHandle(DuplicatedToken);
cleanupServiceToken:
CloseHandle(ServiceToken);
cleanupServiceProcess:
CloseHandle(ServiceProcess);
cleanupService:
CloseServiceHandle(ServiceHandle);
cleanupScm:
CloseServiceHandle(Scm);
cleanupThreadToken:
CloseHandle(ThreadToken);
cleanup:
if (!Ret)
{
RestoreToken(*OriginalToken);
*OriginalToken = NULL;
}
SetLastError(LastError);
return Ret;
}
_Return_type_success_(return != FALSE) BOOL RestoreToken(_In_ HANDLE OriginalToken)
{
RevertToSelf();
if (!OriginalToken)
return TRUE;
BOOL Ret = SetThreadToken(NULL, OriginalToken);
DWORD LastError = Ret ? ERROR_SUCCESS : LOG_LAST_ERROR(L"Failed to restore original token");
CloseHandle(OriginalToken);
SetLastError(LastError);
return Ret;
}
|
