credit to
https://twitter.com/R00tkitSMM ([email protected]) telegram username : https://telegram.me/firozi
Vidix: https://en.wikipedia.org/wiki/Vidix WinIo : http://www.internals.com/
Exploit code for two drivers that share the same piece of code both for direct I/O port and for physical memory access under Windows NT/2000/XP/2003/Vista/7 and 2008.
The exploit uses buffer ovferFlow to gain code execution but the exploit trick is different on x64 and x86.
On x86 I convert Stack OvferFlow to prefect "Write What in Where" condition with "partial stack overflow" and modify some local variable that was used as destination address for memcpy in next code path , finaly abuse nt!HalDispatchTable for gain code execution with this prefect W3 condition we can use Milion way to gain system level like null ACL of other process add ACCESS_MASK to our token ,... saved retuen address was protcted with stack_cookie so we cant modify it
in x64 we cant convert OvferFlow to prefect "Write What in Where" our stack address cant modify other local variable in stack becuse overflow start in higher memory address comper to other local variable( stack grow to lower memory as you know :) so we can just modify return address )
but in this case there wasn't any stack_cookie so we can abuse return address in stack, next challenge was how i can return to user in safe manner or you will see BSOD ? i used KeUserModeCallback for safe return to user mode
what i done:
- find real KeUserModeCallback address in kernel for use in payload
- trigger vulnerability (send ioctl )
what payload do :
- call shellcode ( you can use any shellcode to steal token or disable driver singing enforcement )
- hook PEB->KernelCallbackTable with function that create CMD.exe and exit -- safe exit without BSOD)( i hooked KernelCallbackTable in user mode but after ioctl system fix my hook ?!) so i port it to kernel
- call KeUserModeCallback-> jump to hooked function in user mode (boom :) )
KernelCallbackTable will call KiCallUserMode and you will see floating-point Instructions
nt!KiCallUserMode:
fffff800`016c6840 4881ec38010000 sub rsp,138h
fffff800`016c6847 488d842400010000 lea rax,[rsp+100h]
fffff800`016c684f 0f29742430 movaps xmmword ptr [rsp+30h],xmm6
fffff800`016c6854 0f297c2440 movaps xmmword ptr [rsp+40h],xmm7
fffff800`016c6859 440f29442450 movaps xmmword ptr [rsp+50h],xmm8
fffff800`016c685f 440f294c2460 movaps xmmword ptr [rsp+60h],xmm9
fffff800`016c6865 440f29542470 movaps xmmword ptr [rsp+70h],xmm10
fffff800`016c686b 440f295880 movaps xmmword ptr [rax-80h],xmm11
fffff800`016c6870 440f296090 movaps xmmword ptr [rax-70h],xmm12
fffff800`016c6875 440f2968a0 movaps xmmword ptr [rax-60h],xmm13
fffff800`016c687a 440f2970b0 movaps xmmword ptr [rax-50h],xmm14
fffff800`016c687f 440f2978c0 movaps xmmword ptr [rax-40h],xmm15
fffff800`016c6884 488968f8 mov qword ptr [rax-8],rbp
When the source or destination operand is a memory operand, the operand must be aligned on a 16-byte boundary or a general-protection exception (#GP) is generated.
and
Alignment Most structures are aligned to their natural alignment. The primary exceptions are the stack pointer and malloc or alloca memory, which are aligned to 16 byte, in order to aid performance. Alignment above 16 bytes must be done manually, but since 16 bytes is a common alignment size for XMM operations, this should suffice for most code. For more information about structure layout and alignment see Types and Storage. For information about the stack layout, see Stack Usage.
so stack address must be aligned:) i dont fix this part in my code :)))