The Biggest MFA Misconceptions

By Daniel Zinanti, Information Security Analyst, TraceSecurity

We need to talk about one of the most persistent myths in cybersecurity: the idea that enabling two-factor authentication (2FA) is the same thing as having multi-factor authentication (MFA), and that simply having some MFA magically makes you “secure.”

While MFA is one of the most powerful ways to stop account compromise, it’s not a silver bullet, and not all MFA is created equal. In this post, we’ll bust some common myths, explain what makes MFA effective (and what doesn’t), and wrap up with three quick fixes you can make today to strengthen your defenses.

Myth #1: “We Have MFA Because We Use 2FA”

Let’s clear up the vocabulary first. 2FA is a type of MFA. It’s MFA with exactly two factors. MFA just means more than one factor from different categories. Those categories are:

• Something you know (password, PIN, security question)
• Something you have (smartphone, security token, smart card)
• Something you are (fingerprint, face scan, other biometrics)

So, 2FA is a subset of MFA. If you log in with a password (something you know) and then enter a code from your phone (something you have), that’s 2FA. If you use three factors, for example, a password, a security key, and a fingerprint, that’s MFA too.

The problem is that a lot of organizations check the “MFA” box because they require a second step, but they don’t stop to ask: Is our MFA reducing risk, or just satisfying compliance?

Myth #2: “Any MFA Is Good MFA”

Let’s be honest, some MFA is barely better than nothing. The most common offender? SMS-based 2FA.

Text-message codes were a great step forward ten years ago, but today they’re easily phished, intercepted, and hijacked. SIM-swapping attacks are shockingly common: attackers convince a mobile carrier to port your phone number to their SIM, receive your codes, and stroll into your account.

Compare that to an authenticator app (like Microsoft Authenticator or Google Authenticator) or a hardware security key (like a YubiKey), which are tied to your device and can’t be easily redirected.

Another pitfall – prompt fatigue. Push-based MFA (like “approve sign-in” on your phone) can be abused by attackers who just spam login attempts until a tired user accidentally taps “approve.” That’s how the high-profile Uber breach happened.

In other words, not all MFA provides the same security. Slapping on SMS 2FA and calling it “done” can create a dangerous false sense of safety.

Myth #3: “If We Have MFA, We Don’t Need Anything Else”

Here’s the hard truth: MFA is not a firewall. MFA stops attackers from logging in as you, it does not stop them from:

• Exploiting software vulnerabilities
• Abusing overprivileged accounts
• Moving laterally inside your network once they get in
• Hijacking sessions after authentication

Think of MFA like a deadbolt on your front door – it’s essential, but it doesn’t make your entire house secure if your windows are wide open. Real security comes from layered defenses: patching, access control, monitoring, conditional access policies, user training, and more. MFA is just one (very important) layer.

What Good MFA Looks Like

Let’s look at a few real-world examples to separate strong MFA from weak MFA.

Weak MFA Setup

• Password + SMS code
• Everyone can sign in from anywhere, anytime
• No monitoring of failed MFA attempts
• Users receive unlimited push requests until they approve

Risks

• Susceptible to SIM-swapping and phishing
• No geolocation or device checks to stop suspicious logins

• High chance of MFA fatigue push-approval attacks

Strong MFA Setup

• Password + authenticator app code or hardware key
• Conditional access: only allow logins from trusted devices and locations
• Block legacy protocols that bypass MFA (like IMAP/POP)
• Limit push attempts and alert admins on MFA push spam
• Use number matching (user enters a number shown on the login screen into their app)

Benefits

• Resistant to phishing, SIM swaps, and MFA fatigue
• Stops most credential-stuffing and password-spray attacks
• Adds adaptive, risk-based decision-making to authentication

See the difference? One setup checks a compliance box. The other stops attackers.

Three Quick Fixes to Strengthen Your MFA Today

Here’s the good news: you don’t have to rebuild your security program to level up your MFA. These three changes can make a massive impact quickly:

1. Ditch SMS Codes for Something Stronger

If you’re still relying on text messages, it’s time to move on. Switch users to:

• Time-based one-time passwords (TOTP) from an authenticator app
• Push notifications with number matching
• Hardware security keys for high-privilege accounts

This one change blocks entire categories of attacks, SIM-swaps, SMS forwarding, and phishing kits that target text codes.

2. Add Conditional Access Rules

Don’t treat every login the same. Use your identity provider’s features to:

• Require MFA only on new or risky sign-ins
• Block logins from outside approved countries
• Require device compliance (up-to-date, encrypted) before access

This makes it far harder for attackers, even if they somehow get MFA codes, to get in from an unknown device or location.

3. Close the MFA Bypass Loopholes

Even the best MFA won’t help if attackers can avoid triggering it. Harden your environment by:

• Blocking legacy email protocols like IMAP and POP
• Enforcing MFA on all accounts (including admins and service accounts)
• Limiting MFA prompts per user per time window to stop fatigue attacks
• Enabling sign-in risk monitoring and alerts

Think of this as locking the windows and back doors while your deadbolt is locked on the front.

Final Thoughts

MFA is one of the strongest tools we have in cybersecurity, but it’s not a “set it and forget it” magic shield. 2FA isn’t the same as MFA. And even MFA can be weak if implemented poorly. When you replace SMS codes with phishing-resistant factors, layer in conditional access, and close bypass loopholes, you go from checking the box to stopping attackers. So, let’s retire the myth that “we have MFA so we’re secure” and replace it with a better mantra: “We have smart MFA, so we’re safer.”

Connect with TraceSecurity to learn more.