Tool: pwndbg/gdb

Tool: pwndbg/gdb #

Description #

gdb is a debugger that allows you to inspect a program during runtime. pwndbg is an extension on top of gdb for easy exploit development.

pwndbg/gdb have a number of amazing features and commands, but some core commands include:

  • starti: start the program and stop at the first instruction
  • run: run the program
  • break main: stop at the main function
  • break *0x400412: stop at address 0x400412
  • break *main+84: stop in the main function at offset 84
  • delete 1: delete the first breakpoint
  • c: (continue) after stopping
  • si: execute a single line of assembly
  • n: (next) execute a statement
  • x/s 0x404000: print the string at address 0x404000
  • x/8x 0x7ffcbe6a9000: print 8 bytes of hex at address
  • p 0x404040-0x303030: print the result
  • stack 20: print the first 20 stack entries
  • help x: print the help for examine

Lastly you can open pwndbg at any point from a python script simply by calling:

pwn.gdb.attach(p)

Example # 

#include <stdio.h>
#include <string.h>
// gcc -no-pie -fno-stack-protector -g -o chal chal.c

void func1() {
    char buffer1[8];

    puts("Tell me something interesting:");
    gets(buffer1);
    puts(buffer1);
}

int main() {
    long first = 13;
    char second[16] = "hello world!";
    long third = 0xdeadbeef;

    puts("hi, what is your name:");
    gets(second);

    func1();
}

Files #

Resources #