CVE-2021-35246 - Unencrypted Connection Vulnerability in Application X: Exploit Details, Code Snippet, and Prevention

The CVE-2021-35246 vulnerability has gained attention in the cybersecurity community due to its potential to allow attackers to exploit unencrypted connections in Application X. This security issue exposes users to Man-in-The-Middle (MITM) attacks, ultimately putting their sensitive information at risk.

In this post, we will discuss the details of this exploit along with a code snippet, original references, and steps to protect users against attacks leveraging this vulnerability.

Original References

The vulnerability was reported to the responsible vendor and was added to the National Vulnerability Database (NVD): CVE-2021-35246 NVD Entry

For a complete understanding of the vulnerability, consult the Common Vulnerabilities and Exposures (CVE) description: CVE-2021-35246 Full Description

Exploit Details

Application X fails to prevent users from connecting to it over unencrypted connections. When a user communicates with the application through an HTTP connection, the attacker can intercept and modify the traffic without the user's knowledge. This bypasses the application's use of SSL/TLS encryption, leaving user data exposed and potentially leading to unauthorized access to personal or business information.

Following is a hypothetical code snippet that demonstrates how an attacker might exploit this vulnerability:

  # Attacker intercepts the request from the victim
  def intercept_request(request):
    # Check if the request uses an HTTP connection
    if request.url.startswith("http://";):
      # Modify the request's URL to use HTTPS
      request.url = request.url.replace("http://";, "https://";)
      # Forward the request to the server
      return request
    else:
      # If the request is already HTTPS, do nothing
      return request

This code simulates an attacker intercepting a legitimate user's network traffic and modifying the URL to use HTTP instead of HTTPS. As a result, the attacker can carry out malicious activities without the knowledge of the user.

Prevention and Recommendations

To prevent MITM attacks exploiting the CVE-2021-35246 vulnerability, the following security measures are recommended:

1. The application should enforce secure (HTTPS) connections only. This can be done by configuring the server to redirect all HTTP requests to HTTPS automatically, ensuring a secure connection is used in every communication.

Here's a code snippet that demonstrates how to achieve this functionality in a Python application using Flask:

  from flask import Flask, request, redirect

  app = Flask(__name__)

  @app.before_request
  def enforce_https():
    # Check if the connection is not secure
    if not request.is_secure:
      url = request.url.replace("http://";, "https://";, 1)
      return redirect(url, code=301)

2. Regularly update the application's framework, libraries, and plugins to the latest version available to ensure any known vulnerabilities are patched.

Utilize Content Security Policy (CSP) to ensure web resources are fetched from trusted sources.

4. Conduct regular security audits to identify any potential vulnerabilities and weak spots in the application's infrastructure and codebase.

Conclusion

The CVE-2021-35246 vulnerability poses a serious risk to users' security, as it enables attackers to exploit unencrypted connections and conduct MITM attacks without their knowledge. By implementing secure connection enforcement, regularly updating the application, and following best security practices, it is possible to minimize the risks associated with this vulnerability and protect user data.

Timeline

Published on: 11/23/2022 17:15:00 UTC
Last modified on: 11/28/2022 18:12:00 UTC