Configure MFA For Azure Application Proxy

On the last post we setup Azure Application Proxy to allow internal application’s to be made available externally using AAD integration.

To add additional security to the setup we can enable MFA for the group or users that will be allowed access.

To enable MFA we need to create a conditional access policy and enable on the application proxy.

First step Login to Azure

Go to Azure Active Directory (AAD)AZ1

Go to Enterprise applications

AZ3

Select the Application proxy that will require MFA to be enabledMFA6

Once in the Application proxy go to Conditional Access and select New policyMFA1

Give the policy a meaningful name as it will appear in the overall Conditional Access policy’s aswell as on the Application. This will make it easier to manage if there are multiple policy’s.

Then select Users and groups and select the required users or groupMFA2

Next select the cloud apps that will require MFA in this case it is the Exchange ECP application that was configured previouslyMFA3

We will not setup conditions but if this is required it can be set to only allow access from certain devices types, location & sign-in risk level.

Next go to Access controls and then Grant tab. Select Grant access, tick Require multi-factor authentication and Requires one of the selected controls MFA4

Last step is to Enable the policy

MFA7

Click create at the bottom of the policy

The policy should now show and have tick under Enabled MFA5

Now when we try to access the ECP Application proxy URL,

we should be prompted for MFA MFA8

and asked to register and verify a device to be use for MFAMFA9

It is a good idea to enable MFA for application as it gives an additional layer of security.

Azure Network Security Groups (NSG) to Restrict Management Access

For security reasons it is good practice to lock down access to Azure resources and not leave management ports open to the internet.

One way to restrict access to remote access protocols like RDS / SSH is to create a Network Security Groups (NSG) and apply this to either virtual machines or virtual network subnets.

To create a NSG

Logon on to the Azure portal: https://portal.azure.com

Once logged on go to All Services > Network security groups

If you have created VM’s or other resources there might already be some pre-existing NSG’s.NSG1

To create a new NSG click on Add

Give the NSG a name, assign subscription, resource group and locationNSG2

Once the deployment has completed, click on the NSG this will bring up the configuration page.

First part is to configure the inbound security rules. NSG4

Go to settings > Inbound security rules

Once in Inbound security rules. To add a rule click add.

I want to restrict access to a specific Public IP for RDP access. Set the source as IP Addresses and add in the IP that will be allowed this can be a full range or a single IP depending on network subnet bit. I am only going to add one address so I used /32 below is an example 10.10.10.92/32.

I left source port ranges and destination as default as I don’t want to restrict these.  Choose the required port in this case its 3389, set protocol to Any if you require both TCP/UDP I only need TCP.  Set action to allow, set priority value and last step is give the port a name / description. NSG5

Below is the updated rule I have marked out my public IPNSG6

The outbound rule is set to allow any/any by default so if there is a requirement to lock down certain ports then create a new rule here to block the required ports.

Last step once all rule have been configured is to apply the NSG against resources. I am going to apply the policy to both my subnet and NIC’s assigned to both my test VM’s.

The policy should only need to be applied to either the subnet or VM’s,  I just want to show how to apply to both. If you apply a rule to both VM and subnet they need to match or any port that is not allowed on both wont be work.

To assign to subnet: go to settings > SubnetsNSG7

Select virtual network and subnet. NSG8NSG9

To apply to each VM Nic: Go to settings > network interfaces

As I already had NSG’s associated from the VM deployments I need to re-associate to the new NSG.

Select the NSG of the VM you want to move and go to network interfacesNSG10NSG11

Chose the required NSG

NSG12

Once applied I can now only access the VM’s from my own network.