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What is Broken Authentication Vulnerability and How to Prevent It?

If a hacker successfully logs with stolen credentials, they can misuse your privileges and impact your company's sustainability. Authentication protects a consumer's identity by allowing only a verified user to enter into the system. But there are numerous ways through which a hacker can impersonate consumers and enter inside the system.


No matter what online platforms or applications you use, you are never fully protected against cyberattacks.

Statistics provide testimony to this fact as the number of data breaches rose by 37% in 2020 compared to 2019, and the trend is only increasing.

The first step to protect your organization against such attacks is to have a comprehensive understanding of the issue.

Let us begin by figuring out what is broken authentication.

Very simply put, when the hacker gains access into the system admin's account by using the online platform's vulnerabilities, particularly in two areas: credential management and session management, it's referred to as broken authentication.

Authentication protects a consumer's identity by allowing only a verified user to enter into the system. But there are numerous ways through which the hacker impersonates the consumer and enters inside the system.

The weaknesses inherent in the system, as mentioned above, can be divided into two different groups, namely poor credential management and poor session management.

What is Broken Authentication and Session Management?

Broken Authentication and Session Management is a security vulnerability that occurs when the authentication and session management mechanisms of a web application are flawed or improperly implemented.

Authentication refers to the process of verifying the identity of users, typically through usernames and passwords, while session management involves maintaining and controlling the user's session after authentication.

When these mechanisms are compromised or misconfigured, attackers can exploit the vulnerabilities to gain unauthorized access to user accounts, impersonate other users, or hijack sessions. This can lead to severe security breaches and expose sensitive user information.

What are Some Examples of Broken Authentication Vulnerability?

There are several examples of broken authentication vulnerability that highlight the potential risks. One common example is weak or easily guessable passwords, such as "123456" or "password," which can be exploited by attackers.

Another example is the lack of proper session expiration, where user sessions remain active even after a user logs out, allowing an attacker to reuse the session and gain unauthorized access.

Additionally, if an application does not implement measures to prevent brute-force attacks, attackers can repeatedly guess usernames and passwords until they find a valid combination. Inadequate protection against account lockouts, session hijacking, or session fixation are also examples of broken authentication vulnerabilities.

What Scenarios Can Cause Broken Authentication?

As mentioned earlier, the primary reasons for broken authentication. Let’s understand them one by one.

1. Poor credential management

Consumer credentials can be hijacked to gain access to the system. There are various ways that the hacker can steal critical information, such as the following:

  • Weak passwords: The consumer creates a weak password like '12345' or 'pass123'. The hacker can use various password cracking techniques like rainbow tables and dictionaries to gain access to the system.
  • Weak cryptography: Using weak encryption techniques like base64 and weak hashing algorithms like SHA1 and MD5 make credentials vulnerable. Which is why they must be stored using strong hashing algorithms that make password cracking challenging.

2. Poor session management

Let’s assume you like playing online games. You log in to the application and make several interactions with the network.

The application issues a session ID whenever you log in and records all your interactions. It is through this ID that the application communicates with you and responds to all your requests.

The OWASP broken authentication recommendations state that this session ID is equivalent to your original login credentials. If hackers steal your session ID, they can sign in by impersonating your identity. This is known as session hijacking.

The following points list the scenarios that can cause broken authentication.

  • Weak usernames and passwords.
  • Session fixation attacks.
  • URL rewriting.
  • Consumer identity details aren't protected when stored.
  • Consumer identity details are transferred over unencrypted connections.

What is the Impact of Broken Authentication and Session Management?

If a hacker successfully logs in by stealing your credentials using any of the above mentioned broken authentication techniques, they can misuse your privileges and impact your company's sustainability.

Cybercriminals can have various intentions of hijacking your web application, such as:

  • Stealing critical business data
  • Identity theft
  • Sending fraud calls or emails.
  • Creating malicious software programs for disrupting networks.
  • Cyber terrorism
  • Cyberstalking
  • Selling illegal items on the dark web
  • Sharing fake news on social media

In short, hackers can use broken authentication attacks and session hijacking to gain access to the system by forging session data, such as cookies, and stealing login credentials.

Thus, it would be best if you never compromised with your web applications' security.

A Few Examples of Broken Authentication

Here are a few examples of broken authentication.

Example 1: Credential Stuffing

Suppose you run a departmental store and sell groceries. To grow your business rapidly, you implement a CRM system that stores critical customer data, such as name, phone number, username, and password.

Hackers make their way inside the CRM system and steal all the data. They then use the same credentials — usernames and passwords — to hack into the central bank's database.

In this case, hackers are trying to successfully log in to the central bank's database by hoping that a handful of consumers must be using the same credentials at both places. Such kinds of broken authentication attacks are called credential stuffing.

Example 2: Application session timeouts aren't set properly.

Suppose you go to a cyber cafe and login your Gmail account. After sending the email, you close the browser tab and return home.

Sometime later, the hacker opens your Gmail account and gains access to your crucial information. It happens because your credentials — username and password — haven't been invalidated adequately during logout.

Thus, if the application session timeouts aren't set properly, hackers can execute a broken authentication attack.


Example 3: Passwords are not properly hashed and salted.

Look at the names and their hashes in the following table:

Alice 4420d1918bbcf7686defdf9560bb5087d20076de5f77b7cb4c3b40bf46ec428b
Bob 4420d1918bbcf7686defdf9560bb5087d20076de5f77b7cb4c3b40bf46ec428b
Mike 77b177de23f81d37b5b4495046b227befa4546db63cfe6fe541fc4c3cd216eb9

The hash function stores passwords in the form of a hash instead of plain text, which humans can easily read. But if two different users enter the same password, then their hashes will be exactly the same.

Hackers can perform a dictionary attack and if they crack one password, they can use the same password for gaining access to other accounts that use the same hash.

To prevent this from happening, you must salt the passwords. A salt is a random value that is either appended or prepended to the password and makes it unique. So even if two different users use the same password, their hashes will not be the same.

How to Prevent Broken Authentication?

The following are the ways of preventing broken authentication attacks:

  1. Implement multi-factor authentication (MFA) to verify the consumer's identity. Examples include One-Time Password (OTP) messaged or emailed to the user. This step will prevent brute force attacks, credential stuffing, and stolen credential reuse attacks.
  2. Use weak-password checks by forcing users to include a mix of small letters, capital letters, alphanumeric symbols, and special characters while creating passwords. It would be best to follow NIST 800-63 B's guidelines in section 5.1.1 for memorized secrets.
  3. Place a limit on failed login attempts to 3 or a maximum of 5. Alert the system admin if you detect an attack — brute force, credential stuffing, or any other attack.
  4. Ensure that credential recovery, registration, and API pathways are not vulnerable to account enumeration attacks by using the same message for each outcome.
  5. Generating new random session IDs with high entropy after login protects against hackers. Remember, those session IDs should not be present in the URL and invalidated after logout.

Impact of Broken Authentication

The impact of broken authentication can be severe and far-reaching. When attackers successfully exploit these vulnerabilities, they can gain unauthorized access to user accounts, leading to various consequences.

This may include unauthorized access to sensitive information, such as personal data, financial details, or intellectual property. Attackers can also manipulate or delete user data, impersonate legitimate users, perform fraudulent transactions, or even escalate their privileges within the application.

Furthermore, if the compromised account belongs to an administrator or privileged user, the impact can be even more significant, potentially compromising the entire system or network. Broken authentication vulnerabilities can tarnish an organization's reputation, result in financial losses, and expose users to identity theft and other cybercrimes.

How LoginRadius Protects Against Broken Authentication?

LoginRadius has been at the forefront of offering a multilevel security web app environment. Here is how LoginRadius applications protect against broken authentication:

  • End-to-end SSL encryption for data in transit and ensures protection against unauthorized access.
  • Multi-factor authentication to eliminate the risk of being exposed to attacks.
  • One-way hashing of passwords considerably improves consumer security.
  • Single sign-on (SSO) solution allows users to use the same profile to log in everywhere.


Apart from the steps mentioned in this article, it's essential to train and educate your employees about broken authentication attacks. It would be best if you also employed top-notch cybersecurity measures to protect your company's database from session hijacking, credential stuffing, and other broken authentication attacks.


Q: What is broken access authentication?

A: Broken Access Authentication is a security vulnerability where flaws in the authentication process allow unauthorized access to systems, often due to issues like weak passwords or improper session management.

Q: What is broken authentication in API?

A: Broken authentication in APIs indicates vulnerabilities in their authentication mechanisms, making it possible for attackers to gain unauthorized access and potentially lead to data breaches or compromise sensitive information.

Q: What is a breach of authentication?

A: A breach of authentication occurs when unauthorized individuals exploit vulnerabilities to gain access to systems, risking the compromise of sensitive data and other critical functionalities.

Q: How can we protect against broken authentication?

A: Use strong passwords, enable multi-factor authentication, keep systems updated, secure session management, and conduct regular security audits to guard against broken authentication.

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Deepak Gupta

Written by Deepak Gupta

Deepak is the CTO and co-founder of LoginRadius, a rapidly-expanding Customer Identity Management provider. He's dedicated to innovating the LoginRadius platform. He loves foosball and winning poker games!

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