CWE-209 - Login Form Discloses Password Length Constraints Through Validation Error

(#4229) Bug Closed: Invalid security

1 vote Locked

Reproduction steps

Navigate to the Fluxer login page. Enter a username, such as Admin. Enter a password containing fewer than eight characters, such as 123456. Attempt to sign in or trigger the form's validation. Observe the validation messages displayed beneath the username and password fields.

Expected behaviour

The login interface should provide a clear, user-friendly validation message without exposing raw schema-validation terminology.

Actual behaviour

Should show Invalid login or password

Platform

Self-hosting

  1. Hampus changed the status from Needs triage to Invalid

1 comment

Comment by Hampus
HampusStaff 1 vote
Thanks for the report! This one isn't a security issue, though. Password length limits aren't secret: they're in our source code and our OpenAPI schema, and the registration form shows them too. Knowing that a password must be at least 8 characters doesn't help an attacker, and it doesn't reveal whether an account exists or anything about its password. CWE-209 covers error messages that leak sensitive details, such as stack traces or internal paths, which isn't the case here. If the validation message reads too much like raw schema output, that's fair UX feedback and we can tidy up the wording. If you think you've found a real vulnerability in the future, please email security@fluxer.com instead of posting it publicly, so we can look into it before the details are out in the open.