ZimaOS vulnerable to Username Enumeration via API Responses

ZimaOS is a fork of CasaOS, an operating system for Zima devices and x86-64 systems with UEFI. In version 1.2.4 and all prior versions, the API endpoint http://<Server-IP>/v1/users/login in ZimaOS returns distinct responses based on whether a username exists or the password is incorrect. This behavior can be exploited for username enumeration, allowing attackers to determine whether a user exists in the system or not. Attackers can leverage this information in further attacks, such as credential stuffing or targeted password brute-forcing. As of time of publication, no known patched versions are available.