Microservices Security: Challenges and Best Practices

Learn about 5 key challenges you will face when securing microservices, and best practices to help you overcome them.

What is Microservices Security?

Microservices are small, autonomous services, each of which supports a single function within an application, working together with other microservices. It is a useful design pattern for organizations that need to deliver applications rapidly and with high quality. 

With microservices, it is possible to modify one service without affecting the other services in the application. Microservices applications are commonly built using cloud native technologies like containers and serverless functions.

While there are many advantages to building an application with multiple, distributed components, this also creates security concerns that are different from a traditional monolithic application. Specifically, a complex microservices application can consist of dozens or even hundreds of units, each of which represents an attack surface, and may have its own vulnerabilities and security concerns. 

To run microservices in production, you must take measures to secure every microservice, as well as integration points between microservices. Microservices security can be enormously complex, and to reduce this complexity, you must shift security left and add security measures from the onset of the development process.

In this article, you will learn:

Microservices Security Challenges

There are two approaches to transitioning an app to microservices. Organizations can gradually break a large monolithic project into small instances, or they can architect a new application across discrete services. Either way, each of these smaller components must be managed as an individual project. Here are key challenges organizations can expect when shifting to or building out a microservices architecture.


Isolation is an integral aspect of a microservices architecture. By design, a microservice should be an independent component. This autonomy should be carefully designed into each element, starting from the initial architecture design, across the creation, deployment, maintenance, scaling, and future modifications. The isolation of one microservice should not affect any other microservice, and this principle applies for retired components, as well.

Isolation is especially important for the database layer of the application. Traditionally, all components of a monolithic application can access all databases. This type of architecture can impact long-term performance due to errors and deadlocks. Isolation, which can be achieved with microservices, can help you avoid this issue, as database resources are tied more closely to each service component. 

Of course, on a security level, a large number of microservices creates a bigger attack surface, which means you need to secure more microservices and data stores. However, this might not necessarily translate into greater risk. Isolation means that each microservice cannot access the data of other microservices. This way, even if a microservice is compromised, attackers cannot use it to move laterally.

Deployment can also benefit greatly from isolation. The main purpose here is to deploy each microservice without impacting others, and to ensure it cannot affect other microservices if it fails. Achieving this is especially difficult when dealing with multi-tenant applications, like many Software as a Service (SaaS) products, which require isolation on the data level, as well as the microservices layer.

A Preference for Hybrid Clouds

Cloud-based environments and resources help organizations develop applications at scale. Hybrid cloud and multi cloud deployments have become commonplace, as organizations make use of on-premise investments, while leveraging the advantages of one or more public clouds.

In a multi-cloud implementation, organizations leverage cloud resources from multiple vendors. In hybrid implementations, organizations often combine on-premises and cloud resources together. To secure microservices in hybrid and multi-cloud environments alike, organizations require cloud-agnostic tools they can apply to any environment. Centralization and standardized controls are also needed to effectively achieve uniformity across all cloud environments.

Managing Data Layers

Typically, each microservice maintains its own data source or database. This can lead to data integrity, consistency, and security issues. For example, you often need to ensure that each data store keeps entries once, to avoid redundancy. This can be managed by storing references to data stored by other microservices, rather than duplicating the data on each microservice.

Unsecured DevOps Tools

DevOps teams often use open-source tools that integrate into the CI/CD pipeline. While tooling is critical to achieve the efficiency needed for DevOps pipelines, open source tools do not always prioritize security. 

Before integrating open source tools into your environment, you should carefully assess exposure and then adapt controls before you integrate. You should also continuously evaluate the tools, to ensure relevance and proper security. Since open source tools are often exposed to unknown parties, they may contain vulnerabilities. As part of the assessment and continuous checks, you should also scan for vulnerabilities.

Related content: read our guide to cloud native infrastructure ›

Patterns and Best Practices for Microservices Security

Here are best practices that can help you improve security for your microservices applications.

API Security

APIs are a significant attack vector for every microservices architecture, as the interface point between services. You can use API gateways to improve security. An API gateway serves as a single point of entry handling all external and internal requests. You can use it to prevent clients from directly accessing microservices, to protect against free lateral movement within a microservices architecture, and to reduce the risk of attacks. 

User Authentication and Access Control

To ensure your microservices remain secure, implement measures that protect against improper access. User authentication and access control are especially important for this purpose. Standards-based IAM is critical, for example SAML, WS-Fed, or the OIDC/OAuth2 standards for user authorization. You should also add multi-factor authentication (MFA) to prevent and detect security issues. 

Another way to secure access to microservices is to use Open Policy Agent (OPA), an open source framework that can help you standardize access control across microservices implemented viacloud native technologies such as Kubernetes. 

To learn more, read our detailed guide to Open Policy Agent ›

Practice Defense-in-Depth

A defense-in-depth strategy introduces several security layers into the application. This strategy enables you to provide relevant security for sensitive services, which require a security layer of their own. 

The goal of a defense-in-depth strategy is to prevent potential attackers from exploiting the entire application. If one microservice is exploited, the attacker, ideally, should not be able to move laterally to other services. 

Shift Left

Consider shifting security to the left as an integral part of your process. If you are already running a DevOps team, you already have a culture of collaboration in place. Instead of only including operations and development, you can integrate security and implement DevSecOps strategies. When security is part of the process, you can continuously ensure your microservices are secure and add automation to increase efficiency. 

Microservices Security with Aqua Security

Aqua’s full lifecycle cloud native security approach provides coverage for microservices that have been architected across a cloud native environment, generally via containers and Kubernetes. Aqua also integrates with microservices infrastructure that has been built on top of the cloud native ecosystem, in any cloud platform and orchestrator.

Secure the Build

Aqua accelerates development by detecting security issues in artifacts early and shortening time to remediate. “Shift left” security into the CI/CD pipeline, get full visibility into the security posture of the pipeline and reduce the application attack surface before application deployment.

Secure the Infrastructure

When microservices are built using cloud platforms and orchestrators, Aqua allows teams to enforce compliance across the stack while gaining real-time visibility and control over the security posture of those tools. Teams can monitor, detect, and automatically remediate configuration issues across public cloud services and Kubernetes clusters while ensuring conformity with CIS benchmarks, PCI-DSS, HIPAA, GDPR and other regulations.

Secure the Workloads

Protect applications in runtime using a zero trust model, with granular controls that accurately detect and stop attacks. Unify security across VMs, containers, and serverless on any cloud, orchestrator, and operating system. Leverage micro-services concepts to enforce immutability and micro-segmentation.

Key features: 

  • Vulnerability scanning: Scan CI pipelines and registries, container images, VM images, and functions. Find known vulnerabilities, malware, embedded secrets, OSS licensing, configuration, and permissions issues and prioritize based on potential impact
  • Dynamic Threat Analysis: Detect and mitigate hidden malware and supply chain attacks in container images using a secure sandbox
  • Container Security: Use scan results to set policies for image deployment and prevent the use of unapproved images. Mitigate known vulnerabilities with Aqua vShield, preventing exploits with no code changes. Enforce container immutability by preventing drift against their originating images
  • Kubernetes Security: Kubernetes Security Posture Management (KSPM) ensures ongoing secure configuration with built-in CIS benchmarks, least privilege RBAC, pen-testing, and pod deployment policies.
  • Regulatory compliance: Out-of-the-box policies for PCI-DSS, HIPAA, NIST, and GDPR plus maintain a history of scan results, policy changes, secrets rotation, runtime events and user logins.
  • Identity-based segmentation: Establish zero-trust networking between workloads of the same application identity
  • Other key features that can help in microservices architectures include Cloud VM Security, Serverless security, granular user permissions and multiple integrations across the cloud native ecosystem and platforms