MFA Bypass: Why Your Extra Layer of Security Might Not Be Enough?

Who should read this?

• Individual users – Anyone using MFA to secure personal or work accounts.
• Organizations -Businesses, IT administrators, and employees who rely on MFA to protect company systems and data from unauthorized access.

What is MFA bypass?

Multi-Factor Authentication (MFA) is a security measure that requires users to verify their identity in more than one way at a time—such as by entering a password and approving a login request on their phone. MFA bypass happens when attackers find ways to get around this extra verification step and gain access to accounts as if they were real users. Recently, there has been a sharp rise in these attacks, allowing attackers to break into accounts even when MFA is enabled.
Attackers use different tricks to do this, such as:

• Stealing active login sessions – Attackers grab session cookies from a user’s browser, letting them access accounts without triggering MFA.
• Tricking users into sharing MFA codes – Fake login pages trick people into entering their passwords and MFA codes, which attackers then use to access their accounts.
• Exploiting weaknesses in phone-based MFA – Cyber criminals spam users with repeated MFA requests (push notification fatigue) or take control of a user’s phone number (SIM swapping) to get around MFA.

While MFA remains one of the strongest defenses against unauthorized access, relying solely on it can create a false sense of security, leaving businesses and individuals vulnerable to growing cyber threats.

Studies show that more than 99.9% of compromised accounts didn’t have MFA, making them easy targets. While it’s true that even accounts with MFA are not fully immune to attacks, it is disappointing and alarming that many accounts still don’t have MFA enabled. Organizations must recognize that MFA is just one layer of security—not a complete solution. It’s essential to enable MFA but also to be aware that issues like MFA bypass exist, and additional measures should be taken to ensure better protection.

Why does this happen?

1. MFA is not foolproof – Many MFA methods, such as SMS-based authentication, can be bypassed through SIM swapping or phishing.
2. Users unknowingly help attackers – Many MFA bypass techniques rely on tricking users into approving malicious login requests or entering their MFA codes on fake websites.
3. Attackers steal login sessions – Cyber criminals exploit session cookies stored in browsers, letting them skip MFA and log in without needing additional authentication.

What’s the risk?

• Unauthorized account access – Once attackers bypass MFA, they can steal sensitive data, make fraudulent transactions, or spread malware through compromised accounts.
• Service disruption – Unauthorized access to internal systems can result in operational downtime, preventing employees from accessing essential business applications and disrupting workflow.

How to stay safe?

For individual users

1. Log out when you’re done – Staying logged in makes things easier, but it also gives attackers a way in if they steal your session. Logging out and clearing your cookies now and then helps keep your accounts safe.
2. Don’t approve MFA requests without checking – Some apps allow you to approve logins with a single tap, which attackers can exploit by sending repeated requests. If you receive an unexpected request, always take a moment to verify the request to avoid accidentally granting access.
3. Report unusual activity to your organization’s IT team – Stay alert for any suspicious behavior and notify your IT team right away if you notice anything unusual. This ensures they can take quick action to address potential security threats.

For organizations

1. Limit repeated MFA requests – Attackers may overwhelm users with repeated login requests until one is accidentally accepted. Implementing limits on how many requests can be made within a certain time frame helps protect users from these types of attacks.
2. Allow logins only from trusted devices – To prevent attackers from bypassing MFA using stolen login credentials, ensure that only approved devices are allowed to access critical systems. This added layer of security prevents unauthorized access on untrusted devices.
3. Require periodic re-authentication – If a session is compromised, attackers can continue using it without triggering MFA. Mandating periodic re-authentication for users helps limit access to sensitive systems and ensures that unauthorized access is blocked promptly.
4. Choose the right MFA options for your organization – Text message codes can be stolen if an attacker gains control of a user’s phone number. While authenticator apps are more secure, other methods like hardware tokens and biometrics are also strong options. Evaluate the different MFA methods and choose the one that best fits your organization’s level of security and operational needs.

References

1. Cyber Security News: Pass-the-Cookie Attack Bypass
2. The Hacker News: New 2FA Phishing Kits
3. Forbes: How Hackers Bypass MFA