JWT Security(JWT)
JSON Web Token tokens are used for authentication and must be properly implemented and protected.
What is JWT Security?
In one sentence: JWT is a token for authentication, if not implemented properly hacker can forge it and get into others' accounts!
Imagine you have a membership card that's signed. If you can forge the signature, you can make a fake card and pretend to be a member! JWT is this — it's a token that has a signature. If you don't check the signature properly, hacker can make a fake token.
JWT Structure:
Header: Algorithm and token type Payload: Data (like user_id, role) Signature: Signature for verification
Common JWT Problems:
1. None Algorithm:
Hacker makes algorithm none, removes signature. If server doesn't check, accepts the token!
2. Weak Key: Signature key is short or guessable. Hacker Brute Forces.
3. No Signature Verification: Server doesn't check signature at all!
4. Sensitive Data in Payload: Payload isn't encrypted, only Base64. Anyone can read it!
5. Long Expiry: Token has no expiry date or it's long. If hacker steals it, can use for months!
Why is it important for security?
Because JWT is used for authentication. If hacker forges JWT, can get into anyone's account, even admin!