Buffer Overflow

Fancy way to exploit the buffer

Have you ever heard of buffer overflows?¹ They are a common vulnerability in software that can be exploited to gain unauthorized access to a system. In this post, we will explore how buffer overflows work and how they can be exploited.

What is a buffer overflow?

That is so important! 🆘

#include <stdio.h>
#include <string.h>

void vuln(char *input) {
    char buffer[10];
    strcpy(buffer, input);
}

int main() {
    char input[20];
    scanf("%s", input);
    vuln(input);
    return 0;
}

In the code above, we have a vulnerable function vuln that copies the input string into a buffer of size 10. If the input string is longer than 10 characters, it will overflow the buffer and overwrite the return address of the function. This can be exploited to execute arbitrary code or gain control of the program.

To exploit this vulnerability, we can craft an input string that contains shellcode or a payload that will be executed when the buffer overflows. This is a simplified example, but buffer overflows are a serious security issue that can have severe consequences if not properly mitigated.

Conclusion

A man once said, “With great power comes great responsibility.” - Uncle Ben

You should:

1. Understand how buffer overflows work
2. Follow secure coding practices
3. Use tools like static analysis and fuzz testing to identify and fix buffer overflow vulnerabilities in software

To understand more about buffer overflows, you can check out the following resources.

• Buffer Overflow Attack
• Buffer Overflow Exploitation
• Buffer Overflow Prevention

Footnotes

1. Probably yes, if you are reading this post. ↩