An attacker may perform unauthenticated read and write operations on sensitive filesystem areas via the AppEngine Fileaccess over HTTP due to improper access restrictions. A critical filesystem directory was unintentionally exposed through the HTTP-based file access feature, allowing access without authentication. This includes device parameter files, enabling an attacker to read and modify application settings, including customer-defined passwords. Additionally, exposure of the custom application directory may allow execution of arbitrary Lua code within the sandboxed AppEngine environment.
Users are strongly recommended to upgrade to release version 2.8.0.