Explanation

Box 1: Override
Override: Ignore origin-provided cache duration; use the provided cache duration instead. This will not override cache-control: no-cache.
Set if missing: Honor origin-provided cache-directive headers, if they exist; otherwise, use the provided cache duration.
Incorrect:
Bypass cache: Do not cache and ignore origin-provided cache-directive headers.
Box 2: 1 hour
All media content must expire from the cache after one hour.
Box 3: Cache every unique URL
Cache every unique URL: In this mode, each request with a unique URL, including the query string, is treated as a unique asset with its own cache. For example, the response from the origin server for a request for example.ashx?q=test1 is cached at the POP node and returned for subsequent caches with the same query string. A request for example.ashx?q=test2 is cached as a separate asset with its own time-to-live setting.
Reference:
https://docs.microsoft.com/en-us/azure/cdn/cdn-query-string

Explanation
Objects with secure values are intended to hold sensitive information like passwords or keys for your application. Using secure values for environment variables is both safer and more flexible than including it in your container's image. Another option is to use secret volumes, described in Mount a secret volume in Azure Container Instances.....
https://docs.microsoft.com/en-us/azure/container-instances/container-instances-environment-variables

Explanation
A: Revoke a user delegation SAS
To revoke a user delegation SAS from the Azure CLI, call the az storage account revoke-delegation-keys command. This command revokes all of the user delegation keys associated with the specified storage account.
Any shared access signatures associated with those keys are invalidated.
B: To revoke a stored access policy, you can either delete it, or rename it by changing the signed identifier.
Changing the signed identifier breaks the associations between any existing signatures and the stored access policy. Deleting or renaming the stored access policy immediately effects all of the shared access signatures associated with it.
D18912E1457D5D1DDCBD40AB3BF70D5D
Reference:
https://github.com/MicrosoftDocs/azure-docs/blob/master/articles/storage/blobs/storage-blob-user-delegationsas-
https://docs.microsoft.com/en-us/rest/api/storageservices/define-stored-access-policy#modifying-or-revoking-ast

Explanation

Box 1: Valid root certificate
Scenario: All websites and services must use SSL from a valid root certificate authority.
Box 2: Azure Application Gateway
Scenario:
* Any web service accessible over the Internet must be protected from cross site scripting attacks.
* All Internal services must only be accessible from Internal Virtual Networks (VNets)
* All parts of the system must support inbound and outbound traffic restrictions.
Azure Web Application Firewall (WAF) on Azure Application Gateway provides centralized protection of your web applications from common exploits and vulnerabilities. Web applications are increasingly targeted by malicious attacks that exploit commonly known vulnerabilities. SQL injection and cross-site scripting are among the most common attacks.
Application Gateway supports autoscaling, SSL offloading, and end-to-end SSL, a web application firewall (WAF), cookie-based session affinity, URL path-based routing, multisite hosting, redirection, rewrite HTTP headers and other features.
Note: Both Nginx and Azure Application Gateway act as a reverse proxy with Layer 7 loadbalancing features plus a WAF to ensure strong protection against common web vulnerabilities and exploits.
You can modify Nginx web server configuration/SSL for X-XSS protection. This helps to prevent cross-site scripting exploits by forcing the injection of HTTP headers with X-XSS protection.
Reference:
https://docs.microsoft.com/en-us/azure/web-application-firewall/ag/ag-overview
https://www.upguard.com/articles/10-tips-for-securing-your-nginx-deployment

Explanation
When you run modern, microservices-based applications in Kubernetes, you often want to control which components can communicate with each other. The principle of least privilege should be applied to how traffic can flow between pods in an Azure Kubernetes Service (AKS) cluster. Let's say you likely want to block traffic directly to back-end applications. The Network Policy feature in Kubernetes lets you define rules for ingress and egress traffic between pods in a cluster.
References:
https://docs.microsoft.com/en-us/azure/aks/use-network-policies