Assembly

When debugging binaries during exploit development or wargames, third-party frameworks like GEF, Pwndbg, or Peda provide helpful dashboard views. However, in restricted testing environments, CTF shells, or isolated embedded targets, you may not have internet access or Python dependencies installed to run external tools. You can configure vanilla GDB to provide an automated register and stack inspection view using native define hook-stop hooks in ~/.gdbinit. Custom ~/.gdbinit Configuration Create or update ~/.gdbinit in your home directory: ...

When writing or modifying custom assembly shellcode (such as egg hunters, socket reuse payloads, or stagers), you must verify that the payload functions correctly before embedding it into a full exploit delivery chain. A standard C test harness executes shellcode by casting a char array in memory to a function pointer and calling it directly. The C Test Harness #include <stdio.h> #include <string.h> // Example: Software breakpoint (INT3) or your target shellcode const char shellcode[] = "\x31\xc0\x50\x68\x2f\x2f\x73\x68\x68\x2f\x62\x69\x6e\x89\xe3\x50\x53\x89\xe1\xb0\x0b\xcd\x80"; int main(int argc, char **argv) { printf("Shellcode length: %zu bytes\n", strlen(shellcode)); // Cast the array address to a callable function pointer int (*ret)() = (int (*)())shellcode; // Transfer control flow to shellcode ret(); return 0; } Compilation Flags: Disabling Modern Mitigations Modern compilers enable Stack Canaries and enforce Non-Executable Memory (DEP / NX) by default. If you attempt to execute data placed in the .rodata or .data section without special flags, the kernel terminates the process with a SIGSEGV / segmentation fault. ...