Best Practices for Angular App Security

April 29, 2021 / by Sumit Patil in Angular, Technology

Software security could be a major concern for each application. There are some common vulnerabilities reported for web applications that we need to consider all the applications. In this article, we will discuss the vulnerabilities possible with Angular applications and a way to prevent these vulnerabilities by making use of best practices.

Prevent Cross-Site Scripting (XSS) –

Cross-site scripting (XSS) lets attackers inject client-side script or malicious code into web pages that can be viewed by other users. This sort of attack mostly transpires via:

  1. The query string.
  2. Input field
  3. Request headers

To block XSS attacks, we must stop users from entering malicious code from the DOM. For example, an attacker might enter some script tag to the input field that might render as read-only text.

We should always transform untrusted values, provided by an external user, into trusted values using DomSanitizer. And then bind that value to the inner HTML attribute, passing the HTML string to the service method to get a secured value.

There are two types of methods: sanitize and bypassSecurityTrustX. The sanitize method inspects untrusted value from the context and turns it into a value that’s safe to insert into the DOM.

The bypassSecurityTrustX method inspects untrusted values from the context and according to the value usage, it converts the value into a trusted value. On specific conditions, we might require disabling sanitization. By setting up any one bypassSecurityTrustX methods, We can bypass security by binding the value

  1. Implement Content Security Policies (CSP)
    It adds an extra layer of security which helps to detect and reduce certain types of attacks including data injection and XSS attack. To enable Content Security Policy, our web server (API) must return a proper Content-Security-Policy HTTP header. CSP can be implemented either by using the HTTP Meta tag or defining “Content-Security-Policy” into the header. 

    Content-Security-Policy: script-src ‘self’

  2. Avoid Risky Angular API Endpoints
    Avoid Angular APIs marked within the documentation as “Security Risk.” The foremost common risky API we tend to use is ElementRef. It permits direct access to the DOM and may make your application a lot prone to more XSS attacks. Review any use of ElementRef in your code rigorously. Use this API as a final resort once direct access to the DOM is required. Also, we can use templating and data binding provided by Angular. On the other hand, you can take a look at Renderer2, which has an API that can safely be used even when we don’t have direct access to native elements.
  3. Don’t Customize Angular Files
    It’s a tempting thought to customize Angular libraries to suit your wants, but it will make you dependent on the present version of Angular that you’re using. You’ll notice that it’s tough to upgrade to later versions of Angular and can miss out on crucial security fixes and features. The preferred way to enhance and fix Angular libraries is to share your changes with the community via a pull request. This will allow other developers to review your changes and consider adding them to the consequent version of Angular.
  4. Do not use elements  with Known Vulnerabilities
    There are several third-party library elements available and today it’s tough to develop the application without using such libraries. These libraries might have known vulnerabilities and that might be used by the attacker to inject malicious code or data into the application. These libraries might have security vulnerabilities like CSRF, XSS, buffer overflows, etc.


It’s not rocket science to understand that security is one of the most essential elements of the business and that holds for software development, as well. Simplistic strategies for security can limit the swindle of your economy by glitches and bugs.

It is very obvious that the errors, bugs, patches, or any other mishappenings can’t be isolated from the software or framework. But with fitting security practices and some precautions, you will be capable of tackling the obstacles and implement a more reliable digital solution for your users.

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