Stage File Proxy is a general solution for getting production files on a development server on demand.
The module doesn't sufficiently validate the existence of remote files prior to attempting to download and create them. An attacker could send many requests and exhaust disk resources.
This vulnerability is mitigated by the fact it only affects sites where the Origin is configured with a trailing slash. Sites that cannot upgrade immediately can confirm they do not have a trailing slash or remove the trailing slash to mitigate the issue.
Install the latest version:
- If you use the Stage File Proxy module for Drupal, upgrade to Stage File Proxy 3.1.5
- Greg Knaddison (greggles) of the Drupal Security Team
- Juraj Nemec (poker10) of the Drupal Security Team