What is serverless security?

The advent of serverless architecture has rapidly transformed the development landscape. Developers and IT specialists can focus on building custom applications without managing servers or underlying infrastructure. However, this new freedom raises security challenges for serverless workloads that developers should not ignore. 

In serverless architectures, security responsibilities are divided between the cloud provider and the customer, according to what is known as the shared responsibility model. While cloud providers handle aspects like securing the underlying infrastructure, customers are responsible for securing their applications, configurations, and access controls. Understanding and managing this division of responsibilities is crucial for maintaining a secure serverless environment.

At present, all major cloud providers offer some form of serverless security (such as AWS Lambda, Google Cloud Run functions, and Azure Functions). However, each implementation has the disadvantage of being cloud provider-specific.

Serverless functions present unique security challenges. When operating system (OS)-level management is not a concern, the concerns are reduced to the running code (such as the built package or container) and the access controls to call the serverless function (either through a web call like Amazon API Gateway or via a cloud provider-specific invocation, such as an event). Unlike traditional setups, where security often focuses on maintaining and protecting long-lived resources like virtual machines and on-premises servers, serverless architectures are dynamic and highly ephemeral. This article will cover how security is different in serverless computing, the challenges of serverless security, and how to alleviate these challenges.

How security is different in serverless computing

A significant advantage of serverless computing is its cost efficiency; organizations only pay for the serverless instance while it’s running. However, monitoring the activity of ephemeral containers (where instances only run when triggered) creates challenges. Security monitoring and resource management in a serverless architecture are much more complex than in traditional, long-term monitoring setups. Organizations must have an agent or a monitoring tool that can handle the rapid provisioning and the brief lifespans of serverless containers. This is necessary to ensure comprehensive oversight.

The shared security responsibility between cloud providers and IT specialists for serverless computing can be tricky. Securing workloads involves knowing how to properly configure cloud provider-specific settings and working with the cloud provider in the event of a security issue instead of simply relying on a homegrown IT team.

Decentralization — being able to stand up and compute instances in different regions and availability zones on a whim — is a benefit of being serverless. However, this broad distribution also introduces more potential entry points for attackers. Each instance that spins up in a different location may interact with various services, data stores, or networks, all of which require secure configurations and access controls. Maintaining consistent security policies across this broad environment can become complex, increasing the likelihood of misconfigurations or overlooked vulnerabilities that attackers can exploit. 

Another advantage of serverless computing is the ability to schedule or run function invocations from events. Developers can run serverless functions by putting a message in a queue or uploading a file to a cloud storage bucket. The tradeoff is that these event sources can become attack vectors that threat actors can exploit to invoke malicious functions. This means the event sources require as much security as the serverless functions.

Key security challenges in serverless environments

Moving beyond the architectural-level challenges, let’s consider some key challenges in the serverless security space:

Security tools and technologies for serverless environments

Cloud provider best practices can be enhanced by deploying unified security tooling to monitor for security vulnerabilities and threats across the development life cycle.

Runtime protection continuously monitors serverless deployments, blocks certain calls that a malicious actor might perform on a compromised machine, and alerts the security team the moment something anomalous happens. This protection of your serverless environments also provides security monitoring insights, alerts related to misconfigurations and deployed vulnerabilities, and other relevant security information about containers.

Integration with continuous integration/continuous delivery (CI/CD) pipelines is also essential to the serverless security life cycle. In continuous delivery scenarios, organizations should incorporate serverless security checks early in the development process, where changes are frequently delivered to a production environment.

Get started with CrowdStrike

Serverless architecture presents a way for developers to run their applications without the concerns of server management. It also provides them with the opportunity to take advantage of the cost-effective nature of decentralized, event-based, and ephemeral systems. Though serverless computing offers great flexibility and scalability, security practices specific to serverless computing are required; otherwise, catching issues in this dynamic, event-based environment will prove challenging.

For comprehensive protection, CrowdStrike Falcon® Cloud Security integrates seamlessly with major cloud providers to secure serverless deployments. Start a free trial today and safeguard your serverless functions with confidence.