Impact

An improper implementation was found in the password storage process.

All hashed passwords stored in Shield v1.0.0-beta.3 or earlier are easier to crack than expected due to the vulnerability. Therefore, they should be removed as soon as possible.

If an attacker gets (1) the user's hashed password by Shield, and (2) the hashed password (SHA-384 hash without salt) from somewhere, the attacker may easily crack the user's password.

Patches

Upgrade to Shield v1.0.0-beta.4 or later.

After upgrading, all users’ hashed passwords should be updated (saved to the database).
See https://github.com/codeigniter4/shield/blob/develop/UPGRADING.md for details.

Workarounds

None.

References

• https://cheatsheetseries.owasp.org/cheatsheets/Password_Storage_Cheat_Sheet.html#pre-hashing-passwords
• https://blog.ircmaxell.com/2015/03/security-issue-combining-bcrypt-with.html
• https://www.scottbrady91.com/authentication/beware-of-password-shucking

For more information

If you have any questions or comments about this advisory:

• Open an issue or discussion in codeigniter4/shield
• Email us at security@codeigniter.com