Authentication failures are more common than you think a company I worked with recently had a worrying incident. A hacker got into an admin account even though the login page looked completely secure. The strange part?
No fancy hacking
No malware
No zero-day exploit
The attacker simply found:
- A weak fallback login option
- A password that was reused from another website’s old breach
It was enough to access the entire system.
This is what Authentication Failures are: when a computer system trusts the wrong person.
1. What Is an Authentication Failure?
When you log into an account, the system asks:
“Who are you?”
An authentication failure happens when the system says:
“Yes, you’re allowed in!”
even though the person is not the real owner.
OWASP groups 36 different problems into this category, including:
- Hard-coded passwords
- Sessions that don’t expire
- Weak multi-factor authentication (MFA)
2. How Hackers Break Logins Today
Here are common ways attackers slip in — without hacking the app itself.
2.1 Old / Reused Passwords
If a password is leaked on one site…
…and people reuse it somewhere else…
Attackers try the same passwords everywhere.
Example:"Password1!" → "Password2!"
(Many people only change one character)
2.2 Weak or Broken MFA
Some apps allow a “backup method,” like sending a code to email.
But what if:
- The person’s inbox was already hacked?
- The attacker can forward the emails?
Now MFA doesn’t help.
2.3 Token Confusion
Some sites use the wrong settings for login tokens called JWTs.
If a token for “service A” is mistakenly accepted by “service B”…
hackers jump into the wrong app with a valid token.
2.4 Misconfigured Single Sign-On (SSO)
If apps don’t properly check where a login token came from:
- Attackers copy the token
- Trick users into logging into a fake domain
- Steal access from the real domain
This is very common in large companies.
3. Why Secure Frameworks Aren’t Enough
Even if your app uses a strong authentication library…
Mistakes still happen when:Table
Copy
| Problem | Example |
|---|---|
| People turn off security features | MFA disabled due to “user complaints” |
| Defaults are ignored | Login throttling not set, so unlimited attempts |
| Too many small apps | Each one needs token + session rules |
4. How to Stop Authentication Failures
| What to do | Why it helps |
|---|---|
| Block known bad passwords | Prevents reused breached passwords |
| Use strong MFA (FIDO2 / Passkeys) | Stops phishing and fake login scams |
| Ask for MFA again if behavior changes | Stops session theft |
| Focus on long passwords | Easier to remember, harder to guess |
| Limit login attempts + bot detection | Stops password spraying |
| Store tokens securely | Prevents token theft |
| Check token details carefully | Stops token confusion |
| Rotate sessions often | Token becomes useless quickly |
| Secure account recovery | Hackers can’t reset your password |
| Test logins for abuse in CI/CD | Prevents regressions |
5. Quick Checklist You Can Use Today
- No default admin passwords
- Login page shows a generic error (not which field is wrong)
- Same rate limits for GraphQL and REST
- Tokens expire quickly
- Cookies set to Secure + SameSite
- Scan for leaked secrets each pull request
- Admins must use FIDO2 keys
6. What’s Next
| Trend | Why it matters |
|---|---|
| Passkeys | Password-free future, but old passwords must be disabled |
| AI voice scams | Fake voices can trick phone-based MFA |
| Behavioral biometrics | Promising but must respect privacy and law |
7. Three Things to Do This Week
🔐 Check if Your Password is Leaked
Type your password below (it’s safe – we don’t store it) and see if it’s been hacked before:
Check Now →- Turn MFA on for every important account
- Check passwords against known breached lists
- Do a quick login test to ensure rate limiting works
Final Thought
A login screen is not safe just because it looks safe.
Attackers don’t need to break in through the window.
They simply find someone’s spare key.
Fixing authentication failures is a daily habit, not a one-time task
