UAM Futurama 3 parte 2 partial writeup: ROP contra servidor web sin LEAKS

Introducción

Primero de todo, este no es un write-up completo. Describiré mi exploit para lograr la flag en la segunda parte del reto de Futurama 3 de este mes de la UAM. Se considera el reversing del binario “carl” ya completado y las respectivas vulnerabilidades encontradas para provocar el Buffer Overflow.

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Defeating an ELF32 binary with absolutely no leaks without using the ret2_dlresolve technique

The binary

I was presented with an ELF32 binary with the following protections:

ch77 protections

Disassembling the binary with r2, I quickly recognized a classic stack overflow by abusing the call to read:

There’s a buffer overflow in the read function.

Desclavando espinas 2/3: UAD360 go4fun writeup

El reto

Revisamos la información básica sobre el binario:

file go4fun.uu go4fun.uu: ELF 32-bit MSB executable, MIPS, MIPS32 version 1 (SYSV), statically linked, not stripped

Estamos ante un binario ELF (Linux), con arquitectura MIPS de 32 bits. Además, es Big Endian (MSB).

Ejecutando el binario con arm_now

tonicas | Friday, 21st of June 2019 | Category: analysis, Code | Comments are closed