Microsoft SC-900

Correct. Disk controller firmware is part of the underlying physical/managed infrastructure in Microsoft datacenters. Under the shared responsibility model for IaaS VMs, Microsoft is responsible for maintaining and patching physical hardware and the virtualization layer, including firmware updates that keep the storage platform secure and reliable.

Incorrect. Updating installed applications inside an Azure VM is the customer’s responsibility. In IaaS, Microsoft does not manage the software you install in the guest OS. Customers must patch applications, manage versions, and address vulnerabilities using their own processes or tools like Azure Update Manager and Defender for Cloud guidance.

Incorrect. Configuring permissions for shared folders is an in-guest configuration task (NTFS permissions, SMB shares, local users/groups, or domain-based access). This falls under the customer’s responsibility because it relates to identity/access configuration and data protection within the VM’s operating system environment.

Incorrect. Updating the operating system of an Azure VM (guest OS patching) is the customer’s responsibility in IaaS. Microsoft manages the host OS and hypervisor, but the VM’s OS is administered by the customer, including security updates, configuration hardening, and endpoint protection.