Azure App Service is convenient for any business that has highly unique processes. In-house developers can build in-house apps if nothing is available off-the-shelf to meet a specific need. However, this service is a major DDoS target. That means fully understanding Azure App Service security features is essential.
| “All cloud applications must be developed with a security-first mindset. This process is more efficient and usually cheaper than fixing security issues later.” – Jacob Saunders, EVP of Professional Services, Atmosera |
To protect their Azure apps, many businesses count on TLS (Transport Layer Security). TLS 1.2 is secure but not as advanced as TLS 1.3. So, it’s worth noting that it may or may not block new, emerging threats. Since 95.8% of SSL certificates are still on 1.2, hackers have a lot of room to develop tactics against it. Therefore, most experts recommend a move to 1.3.
Updating your protocols is one way you can make your apps more secure. This article will provide an overview of additional Azure security features and deployment best practices your team should use to optimize your cloud security if you use custom apps.
What is Azure App Service?
Azure App Service is a cloud-based service from Microsoft that allows developers to build and host web applications in various programming languages without managing infrastructure. It supports Windows and Linux and offers auto-scaling, integrated security, and continuous deployment options.
While Azure App Service is automatically integrated with Microsoft Defender and Microsoft Entra ID for access control, developers must also be aware of key security features. Ensuring the right features are designed for your application is critical for ensuring it can perform its intended functions without compromising security.
75% of Applications Have a Detectable VulnerabilityGet help finding them before bad actors do. |
Key Azure Application Security Service Features
Network Control
Azure App Service allows for precise control over who can access your applications by letting you set up static IP restrictions. You can specify allowed or denied IP addresses to block unauthorized personnel or known malicious IPs from accessing your app.
For complete isolation from shared networks, deploy your app in an App Service Environment that resides within a dedicated Azure Virtual Network. This setup provides total isolation and direct access to the resources within the virtual network.
DDoS Protection
Azure’s built-in DDoS protection features filter traffic spikes that can disrupt service availability. Additionally, Azure Front Door extends this protection by using its distributed network of POPs (Points of Presence).
| POPs are strategically located data centers around the world that help distribute network traffic more evenly. They reduce latency and improve speed by routing user requests to the nearest data center. |
DDoS Security Tips
Using Azure’s DDoS protection features in your apps is helpful. However, because Azure apps are such a major DDoS target (Microsoft mitigates 1,700 DDoS attacks daily), it’s important to follow additional best practices instead of relying solely on the technology.
Here are some tips.
| Monitor Traffic | Regularly monitor the traffic to your Azure app. Set up alerts for unusual spikes that could indicate a DDoS attack. |
| Update & Patch | Ensure that your Azure app and its dependencies are up-to-date with the latest security patches. |
| Auto-Scaling | Implement auto-scaling features to handle sudden increases in traffic. While that won’t prevent an attack, it can help mitigate the effects. |
| Rate Limits | Apply rate limiting to sensitive endpoints to prevent abusive behavior and mitigate the risk of DDoS attacks. |
| Layered Security | Combine Azure’s DDoS protection with additional security layers to enhance your defensive posture. |
| Regular Backups | Keep up-to-date backups of your data and applications to ensure that you can quickly recover from any disruptions. |
| Security Reviews | Conduct periodic security reviews and simulations of DDoS scenarios to evaluate your app’s resilience. |
Web Application Firewalls (WAF)
The Azure Web Application Firewall on Azure Application Gateway provides centralized protection of your applications from common vulnerabilities. Azure WAF allows you to define custom rules tailored to your specific security needs (or you can utilize Azure’s rule sets).
Identity Management
Azure App Service is automatically integrated with Microsoft Entra Identity Services. Therefore, you may use Entra ID’s capabilities to control user authentication and authorization for anyone who attempts to access your apps.
HTTPS & Certificates
Azure App Service automatically secures apps with HTTPS. If you add a custom domain to your app, you should add a TLS/SSL certificate to ensure that HTTPS connections remain secure. Doing so enables encrypted communications between client browsers and your custom domain.
Service-to-Service Authentication
Azure utilizes managed identities for authenticating services securely without storing credentials in the code. This reduces the risk of credential leakage and simplifies the authentication process across services.
Secure Connectivity to Remote Resources
Apps can securely connect to remote Azure resources like SQL Databases and Azure Storage without leaving its network. It also enables encrypted connections within Azure for secure access to databases and storage.
Application Secrets Management
Azure App Service also integrates with Azure Key Vault. Through this integration access to sensitive information such as API keys and connection strings is controlled and monitored.
Read More of Our Azure Security Insights |
Azure App Deployment Steps With Security Best Practices
1. Make Sure You Have a Source
Begin by ensuring you have a secure and reliable source for your application. Typically, the deployment source is a repository hosted by version control software such as GitHub, BitBucket, or Azure Repos.
Ensure your repository is restricted to authorized users only. Additionally, always validate any third-party libraries or dependencies before including them in your codebase.
2. Build Your Pipeline
Establish a build pipeline that reads your source code from the deployment source. Configure your build pipeline on a secure build server such as Azure Pipelines, and ensure that the pipeline itself has restricted access. It’s also a good idea to integrate security scanning tools within your pipeline to detect vulnerabilities early.
3. Verify Your Deployment Mechanism
Your deployment mechanism should safely transfer the built application into the /home/site/wwwroot directory of your web app. Use secure deployment mechanisms such as Kudu or Azure Pipelines and, avoid any potentially insecure mechanisms.
4. Deploy a Pilot
Before full deployment, deploy your application to a pilot environment. This is typically a staging slot that mirrors your production environment but is not publicly accessible. Use this pilot to conduct thorough security assessments, including penetration testing and security audits.
Make any necessary adjustments based on the findings to ensure your application is secure before it reaches production. Please note that you will need to conduct multiple rounds of security tests. One study that analyzed 130 open-source JavaScript projects found that 18% of total vulnerabilities originated from changes intended to fix pre-existing vulnerabilities.
| 💡 Remember Continuous Improvement/Continuous Deployment (CI/CD)
The CI/CD principle enhances security in software development by promoting frequent updates and improvements. By continuously deploying updates, teams can swiftly address security vulnerabilities and reduce the risk of threats. |
5. Deploy Actual Release
Once your application has passed all security tests in the pilot phase, proceed with the actual release. Deploy your application into a nonproduction slot first, and then swap it with the production slot to minimize downtime and reduce risk.
Doing so allows you to prepare the application under full production load conditions without exposing it publicly until you confirm its stability and security. Always monitor the deployment closely and be ready to revert if unexpected security issues arise.
Receive Expert Advice & Managed Azure Security Services
No matter how well you secure your custom Azure apps, there’s only so much you can do if your Azure platform is insecure. Pairing the features and best practices from this article with expert-managed Azure security services is what you need to defend your environment.
Atmosera gladly provides platform-level security for Azure. We can also assist you with the DevOps process to ensure security best practices are followed. Alternatively (or additionally), we can update current applications to ensure they meet the latest security standards.