Description
FOSSBilling is a free, open-source billing and client management system. Versions 0.7.2 and prior expose a guest API endpoint, /api/guest/staff/create, intended for initial administrator bootstrap. Due to a flawed admin-existence check, the endpoint remains usable after an administrator already exists. The flawed guard check uses is_countable() on a value that returns a Model_Admin object or null rather than a countable type, causing the expression to always evaluate as true and bypass the intended protection. As a result, an attacker can reach the unprotected endpoint to create a new administrator account and immediately authenticate, gaining a fully privileged admin session even when an admin already exists. This issue has been fixed in version 0.8.0.
Problem types
CWE-288: Authentication Bypass Using an Alternate Path or Channel
CWE-306: Missing Authentication for Critical Function
Product status
References
github.com/...illing/security/advisories/GHSA-28mh-j262-q49w
github.com/FOSSBilling/FOSSBilling/releases/tag/0.8.0