AdGuard Home Authentication Bypass via Path Traversal in Admin-Token Cookie

AdGuard Home, when started with the --glinet flag, contains an authentication bypass vulnerability that allows unauthenticated attackers to gain full admin access by supplying a path traversal sequence in the Admin-Token cookie, exploiting unsanitized string concatenation in the token file path construction within the authglinet middleware. Attackers can craft a request with a traversal payload in the Admin-Token header to redirect file reads to arbitrary paths.