[MEDIUM] SS-2015-014: Vulnerability on 'isDev', 'isTest' and 'flush' $_GET validation

PKSA-wt32-ns28-f45d GHSA-ph62-fv59-vf9h

Affected package: silverstripe/framework

Affected version: >=3.0.0,<=3.0.13|>=3.1.0,<3.1.13

Reported by:
GitHub, FriendsOfPHP/security-advisories