Enable allow list for attachments in ServiceNow instance hardeningIssue Enable deny list for attachments (instance security hardening): This system property controls whether the platform should validate the attachment against the blacklist or not.ResolutionPlease follow the below docs pages which explain the Enable Blacklist property (glide.security.attachment_type.use_blacklist). This will enable the Specify blacklisted extensions (glide.attachment.blacklisted.extensions) property which can be set to a list of disallowed/blacklisted file types: Enable deny list for attachments (instance security hardening) Specify excluded attachment extensions (instance security hardening)If you have further questions, please walk through a scenario such as the following:1) Set glide.security.attachment_type.use_blacklist to true2) Set glide.attachment.blacklisted.extensions property value set to a blacklisted file type such as .exe3) Walk through uploading a .exe file as an attachment to an instance and show that it was blocked in the process by the glide.attachment.blacklisted.extensions propertyRelated Links