Just-in-time (JIT) VM access is a security feature in Azure that allows you to control access to virtual machines (VMs) by providing temporary access to specific ports for a limited time. This feature is designed to reduce the attack surface of your VMs by only allowing access when needed.
Traditionally, when you need to access a VM, you would need to open up the necessary ports to allow traffic to flow in and out of the VM. This creates a security risk as the open ports can be used by attackers to gain unauthorized access. With JIT VM access, you can limit the time that the ports are open, reducing the risk of attack.
JIT VM access works by providing a request-based workflow for requesting access to specific ports on a VM. When a user requests access, the request is reviewed by an Azure Security Center administrator or a custom workflow that you define. If the request is approved, the user is granted access to the VM for a limited time through a secure channel. After the time has elapsed, access to the VM is automatically revoked.
JIT VM access can be configured for Azure VMs running in a virtual network, providing control over inbound traffic to the VM. It can also be configured to use multi-factor authentication for additional security.
Overall, JIT VM access provides a way to limit the attack surface of your VMs while still allowing authorized users to access them when needed. It is a valuable tool for securing your Azure environment and reducing the risk of attack.