Soumettre.fr <= 2.1.5 - Unauthenticated Soumettre Posts Creation/Modification/Deletion

Description

The plugin is vulnerable to unauthorized access and modification of data due to a improper authorization checks on the make_signature function. This makes it possible for unauthenticated attackers to create/edit/delete Soumettre posts. This vulnerability affects only installations where the soumettre account is not connected (i.e. API key is not installed)