Sunshine is a self-hosted game stream host for Moonlight. Starting in version 0.16.0 and prior to version 0.18.0, an attacker may be able to remotely read arbitrary files without authentication due to a path traversal vulnerability. Users who exposed the Sunshine configuration web user interface outside of localhost may be affected, depending on firewall configuration. To exploit vulnerability, attacker could make an http/s request to the `node_modules` endpoint if user exposed Sunshine config web server to internet or attacker is on the LAN. Version 0.18.0 contains a patch for this issue. As a workaround, one may block access to Sunshine via firewall.
The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.