Heap Spraying

Heap Spraying: An Overview

Heap spraying is a method of exploiting computer software vulnerabilities which allows an attacker to execute arbitrary code. It is a technique used to exploit memory corruption vulnerabilities in software, such as buffer overflows, by spraying the heap with data that will cause a program to execute malicious code. By spraying the heap, an attacker can bypass security checks that would otherwise prevent code execution.

Heap spraying is a type of attack that exploits memory corruption vulnerabilities in software. It is a technique used to bypass security checks that would otherwise prevent code execution. By spraying the heap with data, an attacker can cause a program to execute arbitrary code.

Heap spraying is a form of attack that takes advantage of memory corruption vulnerabilities in software, such as buffer overflows. By spraying the heap with data, an attacker can cause a program to execute arbitrary code. This technique is used to bypass security checks that would otherwise prevent code execution.

Heap spraying is a technique used to exploit memory corruption vulnerabilities in software, such as buffer overflows. By spraying the heap with data, an attacker can cause a program to execute arbitrary code. This technique is used to bypass security checks that would otherwise prevent code execution.

The heap spraying process involves sending a large amount of data to the vulnerable program, which is then stored in the program’s heap memory. This data is then used to overwrite the program’s instructions, causing it to execute the malicious code that was contained in the data.

To demonstrate the concept of heap spraying, consider the following example code:

#include <stdio.h>
#include <stdlib.h>

int main()
{
  // Allocate a buffer of size 0x1000
  char *buffer = (char *)malloc(0x1000);

  // Fill the buffer with 0xCC
  memset(buffer, 0xCC, 0x1000);

  // Spray the heap with the buffer
  for (int i = 0; i < 0x1000; i++) {
    free(buffer);
    buffer = (char *)malloc(0x1000);
    memcpy(buffer, &i, 4);
  }

  // Execute the malicious code
  ((void (*)())buffer)();

  return 0;
}

In this example, the attacker is allocating a buffer of size 0x1000 and filling it with 0xCC (the hexadecimal representation of the character “C”). This data is then sprayed onto the heap by repeatedly allocating and freeing the buffer and copying the data into it. Finally, the malicious code is executed by casting the buffer pointer to a function pointer and calling it.

Heap spraying is a powerful technique for exploiting memory corruption vulnerabilities in software. It is a technique used to bypass security checks that would otherwise prevent code execution. By spraying the heap with data, an attacker can cause a program to execute arbitrary code.