Book Image

ASP.NET Core 5 Secure Coding Cookbook

By : Roman Canlas
Book Image

ASP.NET Core 5 Secure Coding Cookbook

By: Roman Canlas

Overview of this book

ASP.NET Core developers are often presented with security test results showing the vulnerabilities found in their web apps. While the report may provide some high-level fix suggestions, it does not specify the exact steps that you need to take to resolve or fix weaknesses discovered by these tests. In ASP.NET Secure Coding Cookbook, you’ll start by learning the fundamental concepts of secure coding and then gradually progress to identifying common web app vulnerabilities in code. As you progress, you’ll cover recipes for fixing security misconfigurations in ASP.NET Core web apps. The book further demonstrates how you can resolve different types of Cross-Site Scripting. A dedicated section also takes you through fixing miscellaneous vulnerabilities that are no longer in the OWASP Top 10 list. This book features a recipe-style format, with each recipe containing sample unsecure code that presents the problem and corresponding solutions to eliminate the security bug. You’ll be able to follow along with each step of the exercise and use the accompanying sample ASP.NET Core solution to practice writing secure code. By the end of this book, you’ll be able to identify unsecure code causing different security flaws in ASP.NET Core web apps and you’ll have gained hands-on experience in removing vulnerabilities and security defects from your code.
Table of Contents (15 chapters)

Fixing open redirect vulnerabilities

A user can be tricked into clicking a link generated from your ASP.NET Core web application, but this can eventually redirect them to a malicious website. Open redirection can happen when a user-controlled parameter determines that the URL to redirect to has no validation or whitelisting. In this recipe, we will remediate the risk of open redirect attacks in code by utilizing safer redirect methods.

First, let's take a look at how an open redirect vulnerability is exploited.

Getting ready

We will use the Online Banking app we used in the previous recipe. Using VS Code, open the sample Online Banking app folder at \Chapter06\unvalidated-redirect\before\OnlineBankingApp\.

You can also perform the steps in this folder for the Fixing open redirect vulnerability recipe.

Testing open redirection

Here are the steps:

  1. Navigate to Terminal | New Terminal in the menu or do this by simply pressing Ctrl + Shift + ' in VS...