ZITADEL 4.0.0 before 4.19.5 Login V2 Account Takeover via Forgeable verificationCheck Cookie

Summary

ZITADEL 4.0.0 before 4.19.5 contains an authentication bypass vulnerability in the Login V2 UI that allows unauthenticated attackers to set the first credential of users lacking any authentication method. Attackers can compute a valid verificationCheck cookie from the user ID and browser fingerprint to set a password, register a passkey, or link an identity provider, taking over the account.

Remediation

1. Inventory every zitadel zitadel deployment, including staging.
2. Upgrade zitadel zitadel to 4.19.5.
3. Confirm the running version after the upgrade.

References

• Advisoryhttps://github.com/zitadel/zitadel/security/advisories/GHSA-84fg-x5h4-w8xv
• Advisoryhttps://www.vulncheck.com/advisories/zitadel-4.0.0-before-4.19.5-login-v2-account-takeover-via-forgeable-verificationcheck-cookie