Skip to content

Authentication bypass vulnerability

Learn more about what an authentication bypass is, why it’s harmful and how to protect your organization from these cyberattacks.

Defend against authentication bypass vulnerabilities
Table of Contents

Authentication bypass vulnerabilities remain common and can cause significant harm. Traditional application defenses are ill-equipped to stop these kinds of attacks, but Contrast Runtime Security makes it much easier to identify and respond to a wide variety of threats.

What is an authentication bypass vulnerability?

An authentication bypass occurs when threat actors are able to bypass the authentication protocols an organization may have in place. For example, let’s say an organization requires someone to enter in their email address and an associated password in order to log in to their financial accounting software. If a threat actor was able to log in to this software without having to enter in validated credentials, it would be considered an authentication bypass.

It’s important to distinguish between an authentication bypass and an authentication bypass vulnerability. An authentication bypass describes any time someone can get around existing authentication protocols. This could include through the use of stolen credentials. An authentication bypass vulnerability, however, describes instances in which an issue with the underlying software enables malicious actors to bypass the existing, set login credentials framework.

How authentication bypass vulnerabilities work

Authentication bypass vulnerabilities occur when an attacker is able to take advantage of a flaw in the software/code and log in even though they are not an authorized user. There is no singular reason why these vulnerabilities may appear or how they are exploited (check out the below examples to see why), but they all represent flaws in how the software is authenticating someone — i.e., in how software is able to know that someone logging in is an authorized user. 

Examples of authentication bypass vulnerabilities 

To get a sense of how authentication bypass issues typically arise, consider these common vulnerabilities:

  • Brute-force attacks: In a brute-force attack, a malicious actor will simply input lots of different options for usernames and passwords until they find an option that works. These kinds of attacks can occur when the application does not limit the number of login attempts and lacks multifactor authentication (MFA).
  • Forced browsing: While this encompasses a variety of vulnerabilities, typically it involves an attacker entering a URL that should only be accessible via a login but which is in fact accessible via other means. For example, let’s say that after someone logs into their online bank account, the URL they see is https://www.bank.com/account-details-12345. If that application was susceptible to forced browsing, then an attacker could simply enter in the above URL and access someone’s bank account without having to log in.
  • Insecure direct object reference: This is a type of forced browsing attack where an attacker can guess a pattern in URLs to log in under false pretenses. Consider the above example: If a malicious actor is able to get into one person’s bank account by navigating  to https://www.bank.com/account-details-12345, they may also be able to log in to other people’s accounts by going to https://www.bank.com/account-details-12346, https://www.bank.com/account-details-12347, etc. 
  • SQL injection: An SQL injection attack consists of an insertion or injection of a SQL query via the input data from the client to the application. SQL commands are injected into data-plane input that affect the execution of predefined SQL commands. Attackers use malicious SQL statements in the input box, and in response, the database presents sensitive information. For more on SQL injections, head here

How to prevent authentication bypass attacks

There are two common options that organizations typically leverage to prevent these kinds of vulnerabilities and attacks:

  • Penetration testing, commonly called pentesting, is the intentional launching of simulated cyberattacks by “white-hat” penetration testers using strategies and penetration-testing tools designed to access or exploit computer systems, networks, websites and applications. Here, the main objective is to identify exploitable issues like authentication bypass vulnerabilities. However, penetration testing can be expensive and time-consuming, and it’s not always perfect. For more on penetration testing, head here.
  • Application Security (AppSec) testing tools like Static Application Security Testing (SAST) and Dynamic Application Security Testing (DAST) are often deployed to review code prior to an application going live. Ideally, these tools would flag potential vulnerabilities so that developers can fix the application prior to its entering the production environment. However, in reality, SAST and DAST all too often miss major issues, create false positives en masse and generate backlogs so massive that developers have no hope of addressing them all, thus leaving issues present in the final live code of an application.

At a minimum, organizations should adopt a strong password policy and require MFA across all applications and systems. But organizations should also be sure to have robust safeguards in place to prevent applications from being impacted by authentication bypass attacks beyond the minimum requirements placed on the end user.

How to mitigate authentication bypass attacks with Contrast Runtime Security

Runtime Security addresses the root cause of AppSec issues by monitoring and protecting applications during their execution. It actively analyzes the application's behavior, data flow and operational context to identify and potentially mitigate or send alerts regarding security threats in real time. 

This approach offers immediate defense against attacks and vulnerabilities like authentication bypass vulnerabilities because it works while the application is running, as opposed to static security measures that are applied during the development phase. It empowers development to enhance application health and enables operations teams to manage AppSec threats more effectively.

See Contrast Runtime Security for yourself