Web application security explained: reviewing WAS testing, best practices, and tools

August 10, 2021  |  Mark Stone

This article was written by an independent guest author.

In today’s corporate environment, business is predominantly conducted online. Most organizations have a website or some type of web application that functions as the hub of their online operations.

Business websites and online applications are necessary for an abundance of important functions — marketing, sales, branding, and much more. If your website is attacked and forced to go down, the impact on your business can be significant.

Attacks are on the rise. In January and February of 2020 alone, the average web app was attacked 20,000 times. Businesses urgently need to consider security in this area, keeping their online operations safe and avoiding devastating damage.

This article will explore some of the common vulnerabilities facing web applications and how to protect against them.

What is web application security?

Web application security is the process of protecting an organization’s websites and online applications. Any business with an online presence is at risk.

Prioritizing web application security must be an essential part of your cybersecurity strategy. Attacks on websites and applications can leave businesses facing significant downtime, huge costs, and permanent reputational damage.

Many never recover.

The web application risk profile – reviewing common vulnerabilities

There are numerous common vulnerabilities facing web applications.

Here is a list of the most significant threats of which you should be aware:

  • SQL injection, where attackers use a malicious SQL code to manipulate a backend database into revealing information. Hackers can then steal sensitive information or tamper with it, all within the application.
  • Remote file inclusion, when an attacker remotely injects a file into a web application server. This allows them to execute malicious scripts, steal data, and inflict severe damage.
  • Distributed Denial of Service (DdoS), where attackers overwhelm a site with huge volumes of traffic, overloading the servers and causing delays and downtime.
  • Memory corruption, when attackers modify a location in your application’s memory, causing problems in the code and leading to unusual and harmful consequences.
  • Poor patching. This one is the easiest to defend against yet is often the most overlooked. Because unfortunately, many web applications are at risk due to outdated security and patching. The cold, hard facts: over 63% of all reported unpatched vulnerabilities are at least two years old, according to Bitdefender, with some dating back well over a decade.

Best practices for web application security

The reassuring news for businesses is that they can defend against vulnerabilities listed above, and it doesn’t require an enormous amount of work and investment to implement basic protections.

Here are some best practices to keep your web applications secure.

Use a reliable WAF (Web Application Firewall)

A Web Application Firewall works by monitoring incoming traffic and blocking attack attempts. It works as a first line of defense, a gateway against incoming attacks, and requires no change to the application itself.

As new threats emerge, WAFs can be configured for specific cases depending on your needs and specific risk profile.

Use web application testing

Web application testing involves testing your web application to ensure it’s working the way it’s intended. This way, you can quickly identify any bugs or vulnerabilities and take the necessary steps to fix them.

Testing should be conducted before release and on an ongoing basis while your application is live. It should be noted that the purpose of web application testing is more than just security, and also covers functionality, usability, and performance.


Shielding-as-a-service is all about having constant, always-on web application testing and mitigation. Shielding-as-a-service is comparable to automated incident response but was built specifically for web applications.

This approach ensures your web applications are always protected, by identifying any threats and taking steps to mitigate them in real-time, around the clock.

AT&T Cybersecurity works with Redshield to ensure our clients’ applications are kept safe through constant monitoring and mitigation. The partnership allows us to meet your organization’s web application security needs as threats evolve and grow in sophistication.

You can read more about Redshield’s approach to shielding here.

Vulnerabilities are common in much more than web applications. For some organizations, managing vulnerabilities may not be difficult. But in many cases, having a trusted partner can be game-changing. Get started with a 30-day free trial of our Managed Vulnerability Program, which combines AT&T's Cybersecurity Consultants' expertise with a portfolio of vulnerability management solutions.

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