The open-source identity infrastructure software Zitadel allows administrators to disable the user self-registration. Versions 4.0.0 to 4.0.2, 3.0.0 to 3.3.6, and all versions prior to 2.71.15 are vulnerable to a username enumeration issue in the login interface. The login UI includes a security feature, Ignoring unknown usernames, that is intended to prevent username enumeration by returning a generic response for both valid and invalid usernames. This vulnerability allows an unauthenticated attacker to bypass this protection by submitting arbitrary userIDs to the select account page and distinguishing between valid and invalid accounts based on the system's response. For effective exploitation, an attacker needs to iterate through possible userIDs, but the impact can be limited by implementing rate limiting or similar measures. The issue has been patched in versions 4.0.3, 3.4.0, and 2.71.15.
ZITADEL is an open source identity management system. Starting in version 2.53.0 and prior to versions 4.0.0-rc.2, 3.3.2, 2.71.13, and 2.70.14, vulnerability in ZITADEL's session management API allows any authenticated user to update a session if they know its ID, due to a missing permission check. This flaw enables session hijacking, allowing an attacker to impersonate another user and access sensitive resources. Versions prior to `2.53.0` are not affected, as they required the session token for updates. Versions 4.0.0-rc.2, 3.3.2, 2.71.13, and 2.70.14 fix the issue.