As the world is moving towards an app-based economy, the threat of cyberattacks is greater than ever. Devices are getting interconnected via IoT, companies are migrating to the cloud, and organizations are relying on apps not just for service delivery but also to run their organizations.
However, this has expanded their attack surface. Various news reports and data also confirm this trend. There has been an alarming rise in data breaches.
According to a Forbes report, in 2023 alone, there has been a massive 72% increase in data breaches since 2021.
At the heart of many of these breaches lies a common vulnerability: broken authentication. This is because the authentication mechanism is an easy target for attackers as it’s exposed to everyone. There are some commonly available tools that hackers use to exploit broken authentication vulnerabilities.
This guide seeks to provide you with an in-depth understanding of broken authentication vulnerability, its causes, various types of broken authentication flaws, and more importantly, strategies and best practices to prevent broken authentication threats.
What is Broken Authentication?
Broken authentication is a critical security vulnerability that plagues many web applications, leaving them exposed to potential cyberattacks. This is among the OWASP Top 10 Vulnerabilities.
This refers to a situation where your web application allows users to access the website via a new account and manages their sessions. Whenever a user logs into their account, a new session ID is created. That session ID is valid only for that particular session.
The purpose of session ID is to identify the user’s session and track their activity on the website. Whenever a user logs in, the web application creates a new session ID and stores it in a cookie on the user’s device. This session ID is then sent to the server with each subsequent request.
The server uses this session ID to determine whether the user is legitimate and they are authorized to access the requested resource. If the user is authorized, the server processes the request and sends a response back to the user.
Now, in case the session ID is intercepted by an attacker, they can use it to impersonate the legitimate user and access their account.
Weak passwords are a prime example of common credential management. Such passwords can easily be exploited by credential stuffing and password spraying attacks. Many times password recovery/reset mechanisms are not secure.
Replace “However, broken authentication is not solely about weak passwords. Improper storage of user credentials is another major culprit.
Relying on weak encryption methods or outdated hashing algorithms, such as MD5 or SHA1, can leave stored passwords open to password cracking attempts. LastPass breach suffered massive breach because of weak password vulnerability.
Understanding the risks and implementing proper safeguards allow CISOs to minimize broken authentication vulnerability threats and better protect users’ and organizations’ sensitive information.
Impact of Broken Authentication
As a CISO, you’re tasked with safeguarding your organization’s digital assets and data. However, the complexity of modern authentication systems makes this task a daunting challenge.
To succeed, your security team needs to prevent this threat every time. However, hackers need to succeed only once, and if they succeed, they can take control of users’ accounts.
Once they enter your system, they can read their sensitive personal data and perform unauthorized actions. The problem is our systems fail to differentiate between attackers’ actions and those of legitimate users. You can imagine the consequences of the same for your organization.
Attackers can successfully exploit these vulnerabilities to gain unauthorized access to sensitive information, manipulate or delete users’ data, impersonate legitimate users, and even escalate their privileges within the system.
For businesses, this can lead to data breaches, financial losses, and severe reputational damage.
Common Causes of Broken Authentication
The primary reason behind the broken authentication can be security flaws in the authentication and session management processes. This may allow threat actors to compromise user credentials or hijack active sessions.
Broken authentication vulnerability often stems from two main areas: poor credential management and inadequate session handling.
Poor Credential Management
Weak credential management practices are a significant contributor to broken authentication vulnerabilities.
This includes:
- Weak passwords that are easily guessable.
- Inadequate protection of stored credentials.
- Insufficient measures against brute-force attacks.
Poor Session Management
Poor session management can lead to session hijacking, and fixation presents serious threats. For instance, if a user logs into their account at a cyber café and forgets to log out, an attacker could later use that same computer to access the user’s account if the application lacks proper session timeout mechanisms.
Session management vulnerabilities can be just as damaging as weak credentials.
Some key issues pertaining to session management include:
- Improper handling of session IDs, which includes issues like using predictable session IDs, failing to properly invalidate old sessions, or transmitting session IDs insecurely.
- Lack of proper session expiration mechanisms that may allow hackers to impersonate legitimate users.
- Vulnerabilities in session token generation and validation.
Types of Broken Authentication Attacks
Here are the different types of broken authentication attacks.

Credential Stuffing
Attackers use lists of stolen username and password combinations to attempt logins across multiple sites. Many users reuse passwords across services, making this attack highly effective at scale.
Password Spraying
Attackers try a small set of common passwords against many accounts. They can bypass account lockout mechanisms and exploit weak password policies.
Session Hijacking
Attackers steal or predict valid session tokens to impersonate legitimate users. It allows attackers to bypass authentication entirely and assume a user’s identity.
Phishing Attacks
Hackers trick users into revealing their credentials through fraudulent emails or websites. It exploits human psychology, making it difficult to prevent through technical means alone.
Examples of Broken Authentication Attack
Here are some common examples of broken authentication attacks:
Scenario #1: If an app does not have protection against automated threats or credential stuffing, hackers can use this app as a password checker to check if the passwords are correct.
Scenario#2: If passwords are the only layer of application security, such attacks can happen. In case users select weak passwords, hackers can easily target them. NIST 800-63 policies advise using multi-factor authentication instead.
Scenario#3: Session timeouts in apps are not always set right. Now, if a user on a public computer is accessing an app and instead of clicking “logout,” they just close the tab and leave. Now, a malicious actor can enter the room using the same browser.
Strategies to Combat Broken Authentication Attacks
To prevent broken authentication, security teams need to implement robust security measures. Multi-factor authentication (MFA) can be a powerful tool in this fight, as this adds an extra layer of security beyond just passwords.
Strong password policies, secure session management practices, and regular security audits are also crucial components of a comprehensive defense strategy.

Implement Multi-Factor Authentication (MFA)
MFA adds an extra layer of security by requiring users to provide two or more levels of verification. This could include a one-time password (OTP) sent via email or SMS, a biometric scan, or a hardware token.
Why it’s effective: Even if an attacker obtains a user’s password, they still can’t access the account because of the additional security layer, significantly reducing the risk of unauthorized access.
Enforce Strong Password Policies
Create and enforce password policies that require:
- A minimum password length (at least 14 characters)
- A mix of uppercase and lowercase letters, numbers, and special characters
- Regular password changes
- Prohibition of common or previously breached passwords
Why it’s effective: Strong passwords are much more resistant to brute-force attacks and dictionary attacks, making it significantly harder for attackers to guess or crack passwords.
Secure Session Management
You can enhance session security by:
- Creating new, random session IDs with high entropy after every login.
- Making sure session IDs are not visible in URLs.
- Establishing appropriate session expiration and timeout policies.
- Invalidating sessions after logout or after a certain period of inactivity.
Why it’s effective: Effective session management minimizes the risk of session hijacking and guarantees that even if a session token is compromised, it will only be useful for a limited time.
Use Secure Password Storage
Use modern, cryptographically secure hashing algorithms such as Argon2id, scrypt, or bcrypt to safely store passwords. Incorporate salting to increase the difficulty of password cracking.
Why it’s effective: Even if an attacker manages to access the password database, robust hashing algorithms render it computationally impractical to reverse the hashes and retrieve the original passwords.
Conclusion
Keep in mind that security is a continuous effort. It’s important to regularly assess and refresh your authentication methods, perform security audits, and stay updated on new threats to uphold a robust security stance.
By employing the right strategies and tools, you can successfully reduce the risks linked to broken authentication and protect your organization’s digital assets.
Don’t let vulnerabilities compromise your app security. Our offensive security can help you fight against hidden threats. Contact us today to know more.