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Web App Security: A Comprehensive Guide to Safeguarding Your Business and Clients' Sensitive Info

In today's world, remote work is the order of the day, and companies are moving to the cloud. And because of this, web apps have revolutionized how businesses interact with customers, making it easier to accomplish tasks faster and with fewer resources.

However, with the transfer of sensitive information online, it is crucial to consider the security of these applications. No web application is entirely safe from attacks, and new threats emerge daily.

This article aims to explore methods for safeguarding your web application and minimizing the risk of data breaches by reducing the attack surface.

How to Secure Web Applications from Vulnerabilities: 16 Web App Security Best Practices

1. Manage Attack Surface and Reduce Unnecessary Codes

Attack surface refers to all the entry points and vulnerabilities in a web application that attackers can exploit.

You can seek external assurance of your attack surface by contracting pen testers and monitoring your changing attack surface by using automated tools to detect and alert to vulnerabilities and misconfigurations.

Another way to manage your web app's attack surface is by following development best practices and ensuring that every code function has a purpose. By removing unnecessary code, services, and plugins, you can reduce your attack surface and remove opportunities for attackers to target your application. This can help reduce the likelihood of successful attacks and increase your web app's security.

2. Use Web Application Firewalls

A web application firewall (WAF) is a security tool designed to protect web applications by monitoring, filtering, and blocking potentially malicious traffic that could exploit vulnerabilities in the application or server. Web application firewalls like open-appsec stand out for their ability to protect web applications from known and unknown web attacks. Web application firewalls can be closed-source or open-source, and each type has its pros and cons.

Note that no web application firewall can guarantee 100% web app security – especially if a web app's source code is plagued with vulnerabilities. But we advise you to use a web application firewall to offer basic and advanced security to your web apps.

Are you looking for a way to block web attacks on your web apps before they happen? open-appsec uses two machine learning algorithms to continuously detect and preemptively block threats before they can do any damage. Our code has also been published on GitHub, and the effectiveness of our WAF has been successfully proven in numerous tests by third parties. Try open-appsec in the Playground today.

What Application Security Best Practices Should You Expect from Your Web Application Firewall Vendor?

Here are some key features you should look out for when choosing a web application firewall vendor:

  1. Regular updates: The vendor should provide regular updates to ensure the WAF is up-to-date with detection capabilities for the latest security threats and vulnerabilities.

  2. Protection against known and unknown threats: The WAF, like open-appsec WAF, should protect your web application from known and unknown threats using techniques like machine learning and behavioral analysis.

  3. Customization: The vendor should offer the ability to customize the WAF's policies to fit your application's specific needs.

  4. Performance: It provides minimal latency with no impact on your web application's performance.

  5. Easy integration: The vendor should provide easy integration with your web app's existing infrastructure, such as load balancers, application servers, and content delivery networks.

3. Input Validation

A web app's input field is one of the most common places attackers target for vulnerabilities. So several web application attacks will inevitably occur in the absence of proper input validation. Some include injections, cross-site scripting, etc.

Proper input validation protects your web app from most attacks mentioned above, enhances data quality and accuracy, and improves application performance. Here are ways to carry out input validation: server-side and client-side validation, input blacklisting and whitelisting, parameter binding, character sanitization, etc.

4. Data Encryption

Data encryption converts sensitive information into an unreadable format to protect it from unauthorized access during transmission or at rest in a web application.

To encrypt data in a web application, you can use encryption algorithms such as Advanced Encryption Standard (AES) with a key that’s ideally 256 bits. You can also use TLS version 1.3 with strong supporting ciphers where possible to secure data during transmission.

5. Use Exception Management

Exceptions are a commonly overlooked aspect of web application security. They are the errors or unexpected events that occur during the execution of a web application's code. Exceptions can be caused by invalid user input, software failures, programming errors, etc.

When not managed, exceptions/error messages may display sensitive information that hackers may use to attack your web app. Therefore, exception management is a web application security method of providing meaningful and generic error messages when a web app request fails. This process helps stop attackers from exploiting vulnerabilities by preventing the leakage of sensitive information (like long stack traces).

To carry out exception management in your web application, you can implement error-handling mechanisms using try-catch blocks and exception-handling frameworks. You can also use logging mechanisms to log errors for review.

6. Apply Authentication and Authorization

Authentication in web applications is the procedure of confirming the identity of a user, while authorization determines what actions a user can perform within your web application.

To authenticate your web application, implement user authentication mechanisms like usernames and passwords or token-based authentication and implement two-factor authentication where possible.

For authorization, It is advised to follow the principle of least privilege, which states that every user and every process should have the minimum permissions necessary to perform their tasks. This principle aims to minimize the potential damage caused by a security breach or a malicious insider attack.

So, to carry out authorization in a web application, you should define access control policies to specify who can access the resources and what actions they can perform.

You can also implement access control measures like regularly reviewing and updating access control policies, conducting access reviews, or using role-based access control (a security model that restricts access to resources based on the roles assigned to individual users or groups).

7. Session Management and Token Expiration

Here's some context: Web apps use session and token-based management implementation methods to provide a more seamless interaction experience for end users, therefore, removing the need to authenticate every interaction within a website.

Since all session tokens are stored roughly in the same place on a user's machine, there are attacks that target authenticated sessions and their tokens, some of which include cookie attacks, session ID guessing, and brute force attacks.

To prevent this, each time a new session is created during the user's request, the previous session has to be deleted from the database, and sessions should have a time limit. Additionally, the session token has to be unique for each user and has to have a complex value that cannot be guessable. Your application should have processes to detect token theft and the ability to revoke sessions and force a re-authentication.

8. Server Security

Servers are frequently targeted to access data stored in an application or to establish a beachhead in a target organization.

To protect your web server, you should harden your operating system, ensuring all unrequired software is removed or disabled. This could be remote registry services, print server services, etc. Also, ensure server administration is done securely using things like jump boxes, just-in-time access, or other privilege access management solutions.

Additionally, try to install all security patches on time, set strong administrative passwords, and ideally use a solution to manage the passwords in this account (an example is LAPS used in Windows servers). Also, we advise you to deploy AV and EDR tools to detect and respond to incidents in your webserver and have a well-documented process for setting up new web apps and servers.

9. Don't Put Sensitive Data in Cookies

Cookies are small pieces of data that a web server sends to a user's browser. They are used in web applications to store the user’s preferences and login information, track user behavior, and personalize the user experience. Aside from its targeted advertising benefits, cookies help personalize your user behavior and help in session management.

Cookies are attractive to attackers because of the user data that are possibly stored in them as well as the opportunity to perform session hijacking attacks. So to mitigate cookies-related risks, it is best practice to avoid storing sensitive data in cookies.

10. Implement HTTPS

HTTPS (Hypertext Transfer Protocol Secure) is a secure version of the HTTP protocol used for communication between web servers and clients. It's best to use HTTPS in your web applications for data transmission to prevent data theft and man-in-the-middle (MITM) attacks and establish trust between the server and client. It uses encryption to protect sensitive data transmitted, such as passwords, credit card numbers, and other personal information.

To implement HTTPS in your web application:

  1. Obtain a TLS certificate from a trusted Certificate Authority (CA) and configure your web server to use the SSL/TLS certificate and enable HTTPS.

  2. Update your website code to use HTTPS URLs instead of HTTP URLs; test your HTTPS setup to ensure everything works correctly.

  3. Don't forget to renew your SSL/TLS certificate before it expires to avoid interruption in your HTTPS service.

11. Quality Assurance and Compliance

In web applications, quality assurance (QA) refers to ensuring that a web application meets predefined quality standards, such as functionality, reliability, compatibility with different platforms and devices, performance, usability, and security. Its goal is to ensure that your web application performs as expected and is secure.

You can do this by incorporating security testing and analysis into your app development process. The QA process involves various techniques, including manual testing, automated testing, unit testing, etc. It also involves tracking and reporting defects or issues and collaborating with the development team to fix them.

On the other hand, compliance in web application security refers to meeting the security requirements set by internal or external policies, regulations, or standards related to web application security.

12. Penetration Testing or Vulnerability Scanning

Penetration testing (pen testing) is a method of testing the security of a web application by attempting to exploit vulnerabilities and weaknesses in the system using automated and manual methods.

On the other hand, a vulnerability scan is an automated security testing method that checks a web app for vulnerabilities and misconfigurations but does not attempt vulnerability exploitation like in penetration testing.

These two testing methods aim to identify vulnerabilities in your web application's security that attackers could exploit and to provide recommendations for improving your application's security. They also support your compliance programs for PCI and HIPAA.

13. Manage Containers Carefully

Using containers in web applications made deploying and scaling web apps easy. It reduces infrastructure costs and enhances resource utilization and portability. Not managing containers well can lead to app performance issues, infrastructure inefficiencies, and, of course, security vulnerabilities.

To properly manage your web app containers, you must use secure and up-to-date container images, and don't forget to scan those images for vulnerabilities before using them. Also, try to use only trusted images that are scanned regularly, implement a secrets management tool, and ensure encrypted communication.

14. Perform a Regular Web Application Security Audit

Once you've launched your web app, the maintenance phase comes next, so you should regularly conduct security audits on an appropriate cadence for the criticality and sensitivity of your web app.

A web application security audit involves a review of your application's architecture, source code, configuration settings, and network infrastructure, as well as testing for vulnerabilities and weaknesses in its functionality, authentication and authorization mechanisms, data handling, and access control.

This audit may also include a review of your company's policies, procedures, and training related to web app security. Remember that a web app security audit aims to identify areas of weakness or vulnerability and provide recommendations for improving your app's security posture.

15. Maintain Security During Web App Development

This can also be called “shift left” and is a practice of ensuring the security of a web app at the development stage. Here, your web app's security is not an afterthought but is being considered from the start of the Software Development Life Cycle (SDLC). Its goal is to discover web app vulnerabilities as early as possible, mitigate them when the cost is not too high, and reduce the chances of getting hit by attacks.

To do this, you can include security experts in your app’s development team to share security understanding and challenge working practices. You can also train your developers on how to use tools like SAST/DAST tools within the development pipeline to catch vulnerabilities early.

16. Content Security Policy

Content Security Policy (CSP) is a security mechanism that allows web application developers to specify which content sources can be loaded on a web page. When implemented, it helps minimize the surface area for attacks and prevent cross-site scripting and sniffing attacks.

CSP defines a set of rules that specify which content can be loaded from which sources. These rules are then communicated to the user's web browser via an HTTP response header. The browser enforces them by blocking content that does not meet the specified criteria.

Please note: CSP is a powerful tool for web application security, but you must implement it carefully to avoid blocking legitimate content.

How open-appsec Keeps Web Applications Secure

open-appsec WAF is a cloud-based web application security solution that shields your web application from known and unknown vulnerabilities. It doesn't rely on signatures to guarantee the security of your application. Instead, it utilizes a pair of machine-learning algorithms, including an offline supervised algorithm and an online unsupervised one.

The supervised offline algorithm has undergone training using millions of malicious and legitimate requests, enabling it to identify attack indicators in incoming requests. Suspicious requests are then forwarded to the second algorithm, while benign requests are granted access to your web server.

On the other hand, the online unsupervised algorithm is designed to minimize the likelihood of false positives by re-examining all suspicious requests flagged by the offline algorithm in the context of your app's structure and user behavior. It subsequently prohibits malicious requests while permitting legitimate ones to interact with your app. Try open-appsec in the Playground today.


Experiment with open-appsec for Linux, Kubernetes or Kong using a free virtual lab

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