Ruby on Rails Security: 8 Best Practices To Create Secure App

Ruby on Rails Security 8 Best Practices To Create Secure App

Ruby on Rails has gained popularity as a web application framework renowned for its security, simplicity, and ease of use.

However, like any other web application, developers need to carefully consider security as a critical aspect during the development process.

People or your targeted audience won’t trust your application, if you haven’t taken app security on a serious major.  

Creating a secure app, ultimately leads to a large number of app downloads.

In this article, we will explore eight best practices to create a secure Ruby on Rails app, ensuring the protection of sensitive data and safeguarding against potential vulnerabilities.

What Is Ruby on Rails?

Technically speaking, a well-known Ruby on Rails is a Rails backend framework for creating web applications built in the Ruby programming language. 

David Heinemeier Hansson created RoR under the MIT License.

Ruby on Rails is suitable with the model-view-controller (MVC) architecture, which provides basic database structure, web pages, and web services.

RoR employs web standards like JSON or XML to transport data and HTML, CSS, and JavaScript to create user interfaces.

Hire RoR Developers on Hourly or Monthly Basis

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Ruby on Rails operates under two guiding concepts, including:

DRY (Don’t Repeat Yourself)

Ruby on Rails adheres to the DRY philosophy of software development to avoid repetition of data and codes.

CoC (Convention Over Configuration)

It offers a variety of suggestions for how to carry out various tasks in a building web application.

Additionally, the 17-year-old Ruby on Rails app web development framework’s seventh version is currently accessible. 

Unlike other web development frameworks, Ruby focuses on simplifying and avoiding repetitious coding.

To begin a RoR project, get in touch with a Ruby on Rails development company. They will take your project and use the RoR framework to satisfy your web app requirements.

Overview: Understanding the Importance of Ruby on Rails Security

Security should be a top priority for any web application, and Ruby on Rails is no exception. 

By following best practices and implementing robust security measures, you can significantly reduce the risk of unauthorized access, data breaches, and other security threats.

Among several frameworks, Ruby on Rails is the preferable choice for developers and many industries such as e-commerce, marketing sites, CMSs, and custom web applications. 

All of this wanted security on high priority! Otherwise, it is hard to convince users to use apps. 

Let’s explore eight essential practices that will help you create a secure Ruby on Rails app.

Ruby on Rails Security: 8 Best Practices

Here, we have listed the eight best practices to create a ruby on rails secure applications, have a look:

1. Model View Controller (MVC)

2. Implementing Strong Authentication Mechanisms

3. Protecting Against Cross-Site Scripting (XSS) Attacks

4. Guarding Against SQL Injection Vulnerabilities

5. Preventing Cross-Site Request Forgery (CSRF) Attacks

6. Utilizing Secure Session Management

7. Implementing Input Validation and Parameter Sanitization

8. Keeping Dependencies Up to Date

Let’s dive into the above-listed practices of Ruby on Rails Security.

1. Model View Controller (MVC):

When a website doesn’t sanitize user input, such as HTML, JavaScript, or VBScript, it becomes vulnerable to exploitation through cross-site scripting.

The Model View Controller in Rails simplifies the process of sanitizing user input because it mandates that all data fetched or stored must pass through a model.

Using the sanitize method, we can additionally sanitize input or output in our view. 

The sanitize method encodes all tags and removes any blacklisted tags.

For illustration, suppose we have typical XSS payloads like:

<img  src=x  onerror=prompt(1)>

<img/src=`%00`  onerror=this.onerror=confirm(1)

<img src=`%00`&Newline; onerror=alert(1)&NewLine;

If you see one of the aforementioned:

<%= sanitize  ‘img src=x   onerror=prompt(1)>’ %>

Rails will automatically make the decision by allowing the img src=x and likely eliminating the event property. Because we have not blacklisted any XSS payloads, Rails will make the decision for us. 

Blacklisting payloads is not something I support; I think it is better to follow secure coding practices. The ruby on rails gems will help us write secure code.

The outcome will appear as follows:

<img src=’’x’’>

When blacklisting and whitelisting XSS payloads, Rails webmasters need to exercise extreme caution. 

JavaScript is a loosely dynamic language, in contrast to SQL.

Thus, we can practically blacklist almost all XSS payloads.

Additionally, some XSS payloads can circumvent validation mechanisms, but that is outside the purview of this paper.

2. Implementing Strong Authentication Mechanisms

Authentication is the process of verifying the identity of users accessing your application. 

It is crucial to implement strong authentication mechanisms for securing rails applications, such as password hashing, salting, and using secure authentication libraries. 

Additionally, enabling features like two-factor authentication (2FA) adds an extra layer of security.

For Example, Role-based Authorization;

Installing CanCanCan:

The Ruby gem CanCanCan offers a straightforward and adaptable mechanism to specify skills and authorization for every role.

To utilize it, you must add this to Gemfile and run a bundle install.

gem ‘cancancan’

Let’s say, If we had an administrator position and a user role, we would specify each role’s capabilities as follows:

class Ability

  include CanCan::Ability

  def initialize(user)

    user ||= # guest user (not logged in)

    if user.admin?

      can :manage, :all


      can :read, :all

      can :create, Post

      can :update, Post, user_id:

      can :destroy, Post, user_id:




In this, we define the skills for the admin and user roles along with an ability class.

A regular user can read all resources, make new posts, update existing posts, and delete their own posts, whereas an admin user can control all resources.

3. Protecting Against Cross-Site Scripting (XSS) Attacks

Cross-Site Scripting (XSS) attacks happen when malicious scripts inject into web pages viewed by users.

To prevent XSS attacks, it is important to sanitize user input and encode output appropriately.

Utilizing Rails’ built-in security mechanisms, such as the sanitize method and output encoding, helps protect your application from XSS vulnerabilities.

Rails automatically escapes all data transferred from Rails to HTML output to guard against XSS attacks.

The victim’s browser reads it as any other HTML code because we utilize legal HTML tags for scripts (). 

For Example, General HTML escaping:

Let’s say that HTML and JavaScript code contain harmful input:

input = “<script>alert(‘XSS’)</script>”

The ERB template writes the following input to the document:

<p><%= input %></p>

Generated Outcome:


The automatic HTML escaping provided by ERB stopped the script injection.

However, it’s typically more difficult!

4. Guarding Against SQL Injection Vulnerabilities

SQL injection attacks happen when users directly concatenate their data into SQL queries, enabling attackers to execute unauthorized database operations.

By using parameterized queries and prepared statements, you can prevent SQL injection vulnerabilities in your Ruby on Rails app. 

ActiveRecord, the default ORM (Object-Relational Mapping) library in Rails, automatically sanitizes input and guards against SQL injection when used correctly.

Examine the ActiveRecord::QueryMethods::WhereChain::where method. This method accesses the WHERE section of a SQL statement and accepts conditions in a number of various formats, including string, array, or hash. 

Sending user_input directly to this method would result in a very simple SQL injection because it attach the string passed this way to the query as a SQL fragment.

Giving attackers such a chance would undoubtedly please them!

Let’s use an illustration to show the point:

User.where(“name = ‘#{params[:name]'”) # SQL Injection!

If name = ‘fff’ when executing this specific line of code, the query will return the following result:

SELECT “users”.* FROM “users” WHERE (name = ‘fff’)

 => #<ActiveRecord::Relation []>

However, if it is set to “‘ OR 1=’1”:

SELECT “users”.* FROM “users” WHERE (name = ‘ ‘ OR ‘1’=’1′)

=> #<ActiveRecord::Relation [#<User id: 1, name:’jack’, …….>]>

As seen above, the successful use of an OR operator made the assault possible, allowing us to retrieve all of the database’s records.

From here on, we can create more complex queries with ease.

Look at the injection-proof variation first.

User.where([“name = ?”, “#{params[:name]}”])

When utilizing the above, SQL Injection is not feasible because the array’s first element is a template and its subsequent elements are parameters to that template.

User.where({ name: params[:name] })

Again, since we clearly set the column name to “name” and assign the external input as its value, this approach avoids SQL injection.

5. Preventing Cross-Site Request Forgery (CSRF) Attacks

Cross-Site Request Forgery (CSRF) attacks trick users into performing unexpected actions on a website without their knowledge or consent. 

To prevent CSRF attacks, Rails provides a built-in protection mechanism called CSRF token verification. 

This feature generates a unique token for each user session and ensures that all incoming requests include the correct token.

Let’s see an example of preventing CSRF attacks, Routing Structure;

We need to reevaluate the routing structure of our website. The initial attack was successful because the system accepted a state-changing operation due to a GET request.

Even beyond the realm of security, we should avoid this structure as it constitutes a harmful habit.

To resolve this, change the route file and configure the application’s action to accept a POST, PUT, or any other protocol based on the type of activity being performed.

Rails.application.routes.draw do    

    root ‘home#index’    

    # get ‘transfer’, to: ‘transactions#create’ # BAD    

    put ‘transfer’, to: ‘transactions#create’ # GOOD


It’s important to note that this method will not prevent the second attack, which originates from a form tag that JavaScript automatically submits a POST for.

In this instance, our user was unable to understand what was happening. 

The attacker can also modify this type of exploit to work with a JavaScript Ajax request and send any protocol or set of arguments required to accomplish the attacker’s objectives.

6. Utilizing Secure Session Management

Proper session management is crucial for maintaining user authentication and preventing session hijacking. 

When implementing session management in Ruby on Rails, it is important to use secure session storage mechanisms, such as encrypted cookies or server-side storage. 

Additionally, session expiration, secure session IDs, and regular session rotation further enhance security.

Here, checkout the session management settings in ruby on rails;

When a user accesses your Rails application, the system automatically establishes a new session for them.

Rails issues each user a special session ID, which it saves in a safe cookie in their browser.

You can utilize the session object in your controllers to save data in the session. 

For illustration, suppose you wish to keep a user’s name in the session after they successfully log in. As an example, you could do this:

def create

  user = User.find_by(email: params[:email])

  if user && user.authenticate(params[:password])

    session[:user_id] =

    redirect_to root_path, notice: “Logged in successfully”

  else[:alert] = “Invalid email or password”

    render :new



Using session[:user_id] =, we keep the user’s user ID in the session in this example after locating the user and confirming their password. This enables us to keep track of the user while they use the application.

7. Implementing Input Validation and Parameter Sanitization

Input validation is essential to prevent malicious data from entering your application. 

By using Rails’ validation helpers and enforcing strict input validation rules, you can mitigate the risk of various security vulnerabilities. 

Additionally, parameter sanitization ensures that user-supplied data is safe to use, protecting against code injection attacks.

You may sanitize user input using a variety of methods and strategies in Rails.

1. Whitelisting User Input

Whitelisting is the technique of limiting user input to only specific letters, numbers, and symbols. 

This method helps to avoid malicious code injection and cross-site scripting (XSS) attacks.

In Rails, you can use the sanitize method to whitelist user input.

Here’s an illustration:

# Sanitize user input

@input = sanitize(params[:input], tags: %w[b i u])

In this case, the sanitize technique only permits the user input to contain the b, i, and u tags.

2. Blacklisting User Input

Blacklisting prevents users from entering specific letters, numbers, and symbols.

This method is effective at thwarting SQL injection attempts.

In Rails, you can use the sanitize_sql method to blacklist user input.

Here’s an illustration:

# Blacklist user input

@input = sanitize_sql(params[:input])

The sanitize_sql method in this illustration forbids any SQL commands in the user input.

3. Parameter Filtering

Parameter filtering, also known as the practice of filtering out sensitive data from user input, includes passwords and credit card details.

In Rails, you can use the filter parameters method to remove sensitive data.

Here’s an illustration:

# Filter sensitive parameters

config.filter_parameters += [:password, :credit_card_number]

The filter parameters method removes the password and credit card number parameters from the user input in this example.

8. Keeping Dependencies Up to Date

Maintaining up-to-date reciprocity is crucial for the security of your Ruby on Rails app. 

Regularly update the Rails framework, along with all associated gems and libraries, to ensure you have the latest security patches and bug fixes. 

Monitoring security advisories and promptly addressing any reported vulnerabilities is essential to keep your application secure.


Ruby on Rails security matters to prevent unauthorized access, protect sensitive data, and keep the trust of users.

Creating a secure Ruby on Rails app requires implementing a combination of best practices, as well as staying up to date with security patches, and following secure coding practices.

By incorporating strong authentication mechanisms, guarding against common vulnerabilities, and diligently maintaining your application’s security, you can build a robust and secure Ruby on Rails application.

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