Serverless is said to improve the security and infrastructure of your applications with their stateless nature of operations. The application is structured into small functions that enable separate units to perform their respective tasks. 

However, the security threat doesn’t eliminate completely but changes the attack surface. 

Since your data resides in the Function-as-a-Service (FaaS) service provider's cloud platform, it becomes more than ever important to have a secured infrastructure. Let’s decode the security angle of serverless in this blog. 

Things to Know about Securing Serverless

Gartner shares: “By 2021, 90% of enterprises using IaaS will also use some serverless PaaS in production, up from 10% at YE17. Through 2022, 80% of successful attacks on serverless PaaS will have a root cause of misconfiguration or the use of known vulnerable code due to immature tools and processes.”

With more and more enterprises embracing the serverless that comes on lower costs and faster delivery rate, there are few factors to be considered in terms of security:

• Developers being the primary drivers of the technology, are pivotal to the security.
• Understand the approaches to protect Serverless without making debugging a complicated process 
• Code injection approaches by vendors should ensure proper architecting that doesn’t hinder the performance or scalability of the serverless.
• Additional security from the developer’s end for the libraries in use should be a norm. 

Security Challenges

A serverless architecture bears a unique set of security vulnerabilities that are consequently prone to threats. The increased number of APIs and cloud storages make it difficult for the conventional firewalls to inspect for warnings. The complex web architecture of the serverless and its functions make it more difficult for the security measures to be carried out. 

These are the top 10 risk factors in serverless architectures:

Challenge #1: Function Event Data Injection

The passing of any input that cannot be trusted directly can pose a risk on execution especially when the execution is triggered by a multitude of event sources. 

Challenge #2: Robust Authentication

A set of robust authentication schemes becomes a mandate when there are distinct serverless functions and public web APIs. The access control and protection of every trigger come under scrutiny with the extra step of authentication. 

Challenge #3: Misconfiguration 

Often while dealing with serverless, the configuration might screw up due to new and critical settings, environments and tasks. The data loss with this misconfiguration threat can be catastrophic. 

Challenge #4: Storage Issues

Increased complexity and scaling leads to storage requirements that can maintain an application’s critical data. The users with access to such critical files should be limited and restrained with encrypted keys and password

Challenge #5: Flow Manipulation

When the functions are divided into microservices like design, the execution flow manipulation becomes a common mishap with multiple types of software. The interlinked functions might invoke two functions simultaneously with one trigger if the applications aren’t coupled in am organized order. 

Serverless Security - Best Practices 

These are few best of industry practices when it comes to securing your serverless applications: 

#1 Function Level Security

As components in serverless are coupled and can get triggered by diverse sources, the attackers get more chances to breach the databases, storages, and critical inputs. A function level security thread needs to be weaved by opting for WAF and API Gateway. 

#2 Minimalist Function

The policies of serverless should be acted upon with care as there are hundreds of permission requirements in each function. Therefore, crafting minimal roles for each function is key. 

As an enterprise, you can adopt compartmentalization with small and viable sets of functions. 

#3 Test it all!

A continuous deployment process can lead to a lack of testing process. It can create opportunities for security breaches to emerge from unknown ends. Therefore, set up a tool that can test and verify the code on a regular basis. This will also enhance the production cycle of your software delivery. 

#4 DoS and DoW attacks

To tackle the Denial-of-Service attacks, organizations opt for auto-scaling the functions of the serverless. However, this makes them open to modern Denial-of-Wallet attacks. In order to mitigate these altogether, you can function self-protection to detect the probable attacks, minimize their impacts, and dynamically adjust scaling choices. 

#5 Credentials and Secrets

Serverless security is best maintained with secrets and credentials that are temporary. With the cloud provider’s key management service, you can encrypt your secrets and retrieve them automatically when needed. Having permanent credentials can erupt risks in terms of third-party services and cross-account integrations. Also, there are other tools that can effectively manage your secrets within the serverless environment.

#6 Continuous Integration 

Seamless distribution of new code via automation can ensure a well-defined deployment with minimum error and manual interference. Automation of the processes makes way for continuous integration and deployment cycles that are scrutinized with a series of scanning, testing, and code analyzing.  

#7 DevOps Workflow

Keeping the DevOps team in the loop of your security adds another layer of protection to your serverless. Integrate the security tool stack with the DevOps workflow and ensure timely detection of any threats that can be prevented with the capabilities of DevOps. 

Conclusion

Being a new technology for many, serverless security remains an issue yet to be addressed with maturity. It requires a range of tactful actions to be taken for the application development lifecycle to be a success. However, with these best practices and a stack of tools, organizations can build and integrate serverless environments without hesitation.