Affected: LibreSpark LibreTV

LibreTV before v2.21.2 contains a server-side request forgery vulnerability that allows authenticated users to bypass checkUpstreamAllowed() by exploiting unpinned DNS resolution in fetchWithSafeRedirects(). Attackers controlling authoritative DNS can return public addresses during validation and internal addresses at connection time via /api/source/test, /api/proxy, /api/search or /api/detail to reach loopback services, private hosts or cloud metadata endpoints.