A security feature bypass exists in Azure SSH Keypairs, due to a change in the provisioning logic for some Linux images that use cloud-init, aka 'Azure SSH Keypairs Security Feature Bypass Vulnerability'.
{ "availability": "No subscription required", "ubuntu_priority": "medium", "binaries": [ { "binary_version": "18.5-45-g3554ffe8-0ubuntu1~16.04.1", "binary_name": "cloud-init" }, { "binary_version": "18.5-45-g3554ffe8-0ubuntu1~16.04.1", "binary_name": "ec2-init" }, { "binary_version": "18.5-45-g3554ffe8-0ubuntu1~16.04.1", "binary_name": "grub-legacy-ec2" } ] }