参考
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Partial RELRO表明got表可写

可以看到是菜单题,有四个功能
分析代码可以知道heaparray是一个全局变量,从0-9先判断该数组是否已填满(10个),未填满则申请0x10大小的内存地址(记为内存1)作为元素值,然后输入size,size作为该内存地址的前0x8字节的值,后0x8字节用来存放malloc(size)返回的内存地址(记为内存2),之后再用read_input(*((_QWORD )(&heaparray + i) + 1), size);往内存2写入东西,写入长度是size。没啥毛病
调用一次create_heap函数如下:

指定heaparray的索引,修改内存2的内容,问题出在read_input(*((void **)*(&heaparray + v1) + 1), *(_QWORD )(&heaparray + v1) + 1LL);这里,读入长度(_QWORD )(&heaparray + v1) + 1LL也就是size+1,会造成off-by-one溢出,我们可以溢出size的低字节,造成chunk extend和overlap
就是打印size和内存2的内容
根据索引删除heaparray对应的内存1和内存2
我们利用三次create_heap功能,得到heaparray[0],heaparray[1],heaparray[2],利用edit_heap的off-by-one,我们可以修改heaparray[1]内存1的size字段,使得heaparray[1]的内存1可以覆盖heaparray[2]的内存1的内容,完成chunk extend和overlap,进而实现任意地址修改,劫持got表拿shell。
先写下程序交互
三次create申请了6个chunk,注意第一个malloc(0x18)会把chunk3的pre_size字段给chunk2用

chunk1的前8字节是记录的size为18,后8字节记录的是chunk2的数据部分地址。

可以看到成功把chunk3的size修改成0x71,chunk3覆盖了chunk4和chunk5


我们重新申请一个0x60大小的内存,并把heaparray[2]的内存1也就是chunk5的后8字节覆盖为put@got。也就是我们可以修改heaparray[1]的内存2内容,从而能够修改heaparray[2]的内存1的内容,注意内存1的后8字节是存放内存2地址的,而我们刚好可以利用edit_heap修改heaparray[2]的内存2的内容,不就能实现任意地址写了。而利用show_heap还能实现任意地址读。

可以看到此时heaparray[2]的内存1的后8字节变成了0x602028,也就是puts@got地址,而我们还可以利用show_heap打印heaparray[2]内存2的内容,这里就是打印puts@got的内容,我们就可以泄露libc基址了。


获取的地址和调试的一样
接着把heaparray[2]的内存1的后8字节变成了0x602018,也就是free@got地址


此时,我们修改heaparray[2]的内存2,其实就是修改free@got的内容,这里修改成system地址

再把heaparray[0]的内存2内容改成/bin/sh,当free(*(heaparray[0]+1))时,其实就是system("/bin/sh")

int menu()
{
puts("--------------------------------");
puts(" Heap Creator ");
puts("--------------------------------");
puts(" 1. Create a Heap ");
puts(" 2. Edit a Heap ");
puts(" 3. Show a Heap ");
puts(" 4. Delete a Heap ");
puts(" 5. Exit ");
puts("--------------------------------");
return printf("Your choice :");
}
int menu()
{
puts("--------------------------------");
puts(" Heap Creator ");
puts("--------------------------------");
puts(" 1. Create a Heap ");
puts(" 2. Edit a Heap ");
puts(" 3. Show a Heap ");
puts(" 4. Delete a Heap ");
puts(" 5. Exit ");
puts("--------------------------------");
return printf("Your choice :");
}
int __fastcall main(int argc, const char **argv, const char **envp)
{
char buf[8]; // [rsp+0h] [rbp-10h] BYREF
unsigned __int64 v5; // [rsp+8h] [rbp-8h]
v5 = __readfsqword(0x28u);
setvbuf(_bss_start, 0LL, 2, 0LL);
setvbuf(stdin, 0LL, 2, 0LL);
while ( 1 )
{
menu();
read(0, buf, 4uLL);
switch ( atoi(buf) )
{
case 1:
create_heap();
break;
case 2:
edit_heap();
break;
case 3:
show_heap();
break;
case 4:
delete_heap();
break;
case 5:
exit(0);
default:
puts("Invalid Choice");
break;
}
}
}
int __fastcall main(int argc, const char **argv, const char **envp)
{
char buf[8]; // [rsp+0h] [rbp-10h] BYREF
unsigned __int64 v5; // [rsp+8h] [rbp-8h]
v5 = __readfsqword(0x28u);
setvbuf(_bss_start, 0LL, 2, 0LL);
setvbuf(stdin, 0LL, 2, 0LL);
while ( 1 )
{
menu();
read(0, buf, 4uLL);
switch ( atoi(buf) )
{
case 1:
create_heap();
break;
case 2:
edit_heap();
break;
case 3:
show_heap();
break;
case 4:
delete_heap();
break;
case 5:
exit(0);
default:
puts("Invalid Choice");
break;
}
}
}
unsigned __int64 create_heap()
{
__int64 v0; // rbx
int i; // [rsp+4h] [rbp-2Ch]
size_t size; // [rsp+8h] [rbp-28h]
char buf[8]; // [rsp+10h] [rbp-20h] BYREF
unsigned __int64 v5; // [rsp+18h] [rbp-18h]
v5 = __readfsqword(0x28u);
for ( i = 0; i <= 9; ++i )
{
if ( !*(&heaparray + i) )
{
*(&heaparray + i) = malloc(0x10uLL);
if ( !*(&heaparray + i) )
{
puts("Allocate Error");
exit(1);
}
printf("Size of Heap : ");
read(0, buf, 8uLL);
size = atoi(buf);
v0 = (__int64)*(&heaparray + i);
*(_QWORD *)(v0 + 8) = malloc(size);
if ( !*((_QWORD *)*(&heaparray + i) + 1) )
{
puts("Allocate Error");
exit(2);
}
*(_QWORD *)*(&heaparray + i) = size;
printf("Content of heap:");
read_input(*((_QWORD *)*(&heaparray + i) + 1), size);
puts("SuccessFul");
return __readfsqword(0x28u) ^ v5;
}
}
return __readfsqword(0x28u) ^ v5;
}
unsigned __int64 create_heap()
{
__int64 v0; // rbx
int i; // [rsp+4h] [rbp-2Ch]
size_t size; // [rsp+8h] [rbp-28h]
char buf[8]; // [rsp+10h] [rbp-20h] BYREF
unsigned __int64 v5; // [rsp+18h] [rbp-18h]
v5 = __readfsqword(0x28u);
for ( i = 0; i <= 9; ++i )
{
if ( !*(&heaparray + i) )
{
*(&heaparray + i) = malloc(0x10uLL);
if ( !*(&heaparray + i) )
{
puts("Allocate Error");
exit(1);
}
printf("Size of Heap : ");
read(0, buf, 8uLL);
size = atoi(buf);
v0 = (__int64)*(&heaparray + i);
*(_QWORD *)(v0 + 8) = malloc(size);
if ( !*((_QWORD *)*(&heaparray + i) + 1) )
{
puts("Allocate Error");
exit(2);
}
*(_QWORD *)*(&heaparray + i) = size;
printf("Content of heap:");
read_input(*((_QWORD *)*(&heaparray + i) + 1), size);
puts("SuccessFul");
return __readfsqword(0x28u) ^ v5;
}
}
return __readfsqword(0x28u) ^ v5;
}
unsigned __int64 edit_heap()
{
int v1; // [rsp+Ch] [rbp-14h]
char buf[8]; // [rsp+10h] [rbp-10h] BYREF
unsigned __int64 v3; // [rsp+18h] [rbp-8h]
v3 = __readfsqword(0x28u);
printf("Index :");
read(0, buf, 4uLL);
v1 = atoi(buf);
if ( (unsigned int)v1 >= 0xA )
{
puts("Out of bound!");
_exit(0);
}
if ( *(&heaparray + v1) )
{
printf("Content of heap : ");
read_input(*((void **)*(&heaparray + v1) + 1), *(_QWORD *)*(&heaparray + v1) + 1LL);
puts("Done !");
}
else
{
puts("No such heap !");
}
return __readfsqword(0x28u) ^ v3;
}
unsigned __int64 edit_heap()
{
int v1; // [rsp+Ch] [rbp-14h]
char buf[8]; // [rsp+10h] [rbp-10h] BYREF
unsigned __int64 v3; // [rsp+18h] [rbp-8h]
v3 = __readfsqword(0x28u);
printf("Index :");
read(0, buf, 4uLL);
v1 = atoi(buf);
if ( (unsigned int)v1 >= 0xA )
{
puts("Out of bound!");
_exit(0);
}
if ( *(&heaparray + v1) )
{
printf("Content of heap : ");
read_input(*((void **)*(&heaparray + v1) + 1), *(_QWORD *)*(&heaparray + v1) + 1LL);
puts("Done !");
}
else
{
puts("No such heap !");
}
return __readfsqword(0x28u) ^ v3;
}
unsigned __int64 show_heap()
{
int v1; // [rsp+Ch] [rbp-14h]
char buf[8]; // [rsp+10h] [rbp-10h] BYREF
unsigned __int64 v3; // [rsp+18h] [rbp-8h]
v3 = __readfsqword(0x28u);
printf("Index :");
read(0, buf, 4uLL);
v1 = atoi(buf);
if ( (unsigned int)v1 >= 0xA )
{
puts("Out of bound!");
_exit(0);
}
if ( *(&heaparray + v1) )
{
printf("Size : %ld\nContent : %s\n", *(_QWORD *)*(&heaparray + v1), *((const char **)*(&heaparray + v1) + 1));
puts("Done !");
}
else
{
puts("No such heap !");
}
return __readfsqword(0x28u) ^ v3;
}
unsigned __int64 show_heap()
{
int v1; // [rsp+Ch] [rbp-14h]
char buf[8]; // [rsp+10h] [rbp-10h] BYREF
unsigned __int64 v3; // [rsp+18h] [rbp-8h]
v3 = __readfsqword(0x28u);
printf("Index :");
read(0, buf, 4uLL);
v1 = atoi(buf);
if ( (unsigned int)v1 >= 0xA )
{
puts("Out of bound!");
_exit(0);
}