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The complexities of serverless security

The complexities of serverless security

Serverless computing is a cloud-native model that allows developers to write code and deploy applications without needing to manage servers and other infrastructure running the services. Though you’re technically still working with servers, there’s also a cloud provider managing and provisioning the infrastructure on your behalf. 

This serverless ecosystem has numerous benefits, such as faster auto-scaling, quicker time to market and better cost optimization. Additionally, you only have to pay for the computing resources you need, and you won’t incur costs for idle servers. These benefits, among many more, are why serverless architecture remains popular among developers.

Because you’re using servers and working with a cloud provider, serverless computing uses a shared responsibility approach to managing security. The cloud service provider secures most of the underlying infrastructure while the client oversees the application’s safety, data, compliance requirements, and other services. Protecting your code, business logic, data, and other application-specific functions remains your responsibility. 

This shared security responsibility approach brings about significant complexities that need a different procedure to mitigate. For example, because developers don’t have total control over infrastructure configurations, you can secure your application but still be susceptible to your vendor’s vulnerabilities. 

Another complexity is that serverless has a multitude of independent components that increase the attack surface, further complicating your security strategies. Coupled with the existing challenges faced by traditional applications, serverless security requires an approach that consistently evolves with the dynamic nature of serverless architecture.

These are some of the security challenges that developers face with serverless deployments. This article explores more of these challenges and the advantages of the serverless approach. It also discusses potential vulnerabilities that accompany serverless architectures and how to secure your serverless applications.

Challenges in securing serverless applications

Serverless infrastructures are becoming an increasingly popular choice, largely due to their lightweight, scalable design without the hassle of managing the underlying architecture. Serverless also has near-infinite scaling capacity that can handle large workloads with minimal downtime. This capacity contributes to enhanced productivity since you can now focus on writing and executing business logic that adds tangible value to the business.  

Serverless security requires different strategies working together to secure the variety of components found on serverless platforms. Because these form potential attack surfaces, you need tactics that can secure your business logic, application programming interfaces (APIs), dependencies, third-party libraries and numerous micro-components. 

Serverless architecture

To grasp the depth of the security measures needed in a serverless environment, you need a thorough understanding of how serverless architecture works.

Serverless mainly operates through event-driven executions, meaning functions that are executed when a developer or a piece of code triggers an event. There are five core components that run these events:

  • The client application: The client sends HTTP requests to an API endpoint through their application.
  • Web server: The web server hosts and serves all your static files from this server.
  • Serverless provider (function as a service [FaaS]): This layer involves executing business logic through cloud vendors such as Google Cloud Functions, AWS Lambda and Microsoft Azure Functions. 
  • Database: The vendor also offers a cloud-based database that eliminates the need to manage your database.

The transient nature of serverless reduces the risk of attackers injecting malware because functions run for a while before restarting. Another security advantage is that you don’t manage the core infrastructure, so you benefit from security practices created by your service provider at a fraction of the cost. 

Serverless potential vulnerabilities

While the architecture of the serverless approach has inherent security advantages, it also raises new security issues. Let’s explore several possible vulnerabilities. 

Broken authentication

Serverless uses a microservice system where several distinct components, all with their purpose, work together to form the overall architecture. Enforcing authentication policies for all the different features is complex, and failure to execute the various security schemes may expose the microservices to attacks.

Event data injection

Serverless has multiple event sources for triggering functions. These sources often use different message formats, which attackers can easily inject with harmful code that executes commands remotely to compromise applications.

Insecure serverless configurations and dependencies

Serverless platforms come preinstalled with custom security configurations that you must adapt to your application’s security parameters. Failure to do so may result in an insecure platform with vulnerabilities that trickle down to your code. 

Unintended privileges for functions

Unintended privileges occur when you unintentionally grant access to certain functions that shouldn’t be accessible to the general user. Unintentionally giving access happens because managing security for all serverless components can be tedious. Lack of oversight and monitoring can result in attackers targeting sensitive parts that lack strict permissions.

How to secure serverless applications

Securing serverless applications requires much more effort, even if the cloud service provider takes care of the underlying platform. You must still do regular audits, patch vulnerabilities, assign permissions and more. 

Your effort to secure your applications could quickly negate the time and costs saved from choosing a serverless platform over a traditional cloud platform. 

So, what’s the next best solution? An effective serverless security solution frees you from the added burden of tuning your application’s security to adapt to a serverless environment. You do this by managing the security of your complete development pipeline while monitoring vulnerabilities and threats in real-time. Implementing such a solution requires a dedicated team of professionals working round the clock to secure applications. 

Contrast Security achieves airtight application-level security through:

  • Implementing fast and accurate application testing
  • Performing real-time scanning to fix vulnerabilities as they come up
  • Offering always-on protection that reduces lengthy security fire drills
  • Providing continuous observability from within your applications


Securing your serverless architecture requires an approach to security that caters to the event-driven, single-purpose nature of serverless computing. Also, your service provider mainly oversees the overall infrastructure’s security with the expectation that you understand your responsibility in securing your platform. These complexities are why serverless applications need real-time solutions to detect and resolve code-level threats. 

It’s not enough to use traditional security methods. You need a unified solution that evolves with dynamic serverless environments while empowering developers to protect their code throughout the development pipeline. 

A serverless security approach should also offload application-side security tasks so you can focus on business logic and value-addition.

To learn more about securing your serverless applications, get started with Contrast Security.

Sharon Dagan, Director for Cloud Native/Serverless, Contrast Security

Sharon Dagan, Director for Cloud Native/Serverless, Contrast Security

Sharon Dagan is the Director for Cloud Native/Serverless at Contrast Security. Prior to joining Contrast, Sharon was a lead product manager of several of today’s leading products in zero-trust technologies, threat modeling/hunting and digital identity fraud detection. Sharon is a certified Ethical Hacker and holds a Bachelor of Science degree in Electrical Engineering from Tel-Aviv University.