Kavita < 0.5.4.1 Unauthenticated Path Traversal via cover-upload Endpoint

Kavita 0.5.2 before 0.5.4.1 contains a path traversal vulnerability that allows unauthenticated attackers to read arbitrary files by supplying '../' sequences in the filename parameter. Attackers can send GET requests to /api/image/cover-upload with filename values like ../appsettings.json to retrieve configuration files outside the temp directory. Exploitation evidence was first observed by the Shadowserver Foundation on 2023-10-18.