Serverless computing comes with several benefits: operational cost reduction and the ease of scaling at the very top. The main security challenges, therefore, are toward a novel, dynamic and distributed nature. With the increasing adoption rate for serverless architectures, robust security practices are necessary in order to help protect the application and its data. In this article, we discuss key practices on how to secure serverless applications and infrastructure.
Understanding Serverless Security Challenges
An architecture to be noted about serverless security is that it greatly differs from that of a traditional infrastructure. On the other hand, in a serverless setup, the major part of the infrastructure is an area maintained by the provider—servers, operating systems and runtime environments. This shifting of responsibilities leads to some of the security tasks moving to the provider side while new challenges are created.
First of all, the expanded attack surface would be a real challenge. Most of the time, serverless applications consist of multiple services, such as an API gateway, databases, or third-party integrations. Most of these components are possible points of vulnerability. Besides, one small nature of serverless functions is that they are meant to be small and short-lived pieces of code and it becomes hard to maintain visibility and ensure that security policies are consistent throughout all the functions.
For example, in a 2024 report, the Cloud Security Alliance pointed out that 75% of organizations had already suffered one or more security incidents with their serverless deployments. Most of the incidents were caused by misconfigurations, insecure third-party dependencies and a lack of proper monitoring. The first key in building a practice for serverless applications is to understand these challenges.
Identity and Access Management (IAM) Best Practices
Effective identity and access management (IAM) in a serverless environment ensures the protection and security of your resources. IAM controls who can access your resources and what actions they can be allowed to perform—therefore, it forms the cornerstone of serverless security.
Always apply the principle of least privilege to reduce possible risks, that is, give users and functions only enough access to do the needed actions. Over-permissive IAM roles can be used maliciously when they fall into the wrong hands. For example, a very permissive function, if compromised, could be used to access sensitive data or resources.
For instance, a Gartner study in 2024 noted that 85% of all cloud-security-related incidents are due to misconfigured IAM roles. Audit and review IAM policies regularly and use automated policies if possible, which are capable of scanning for and fixing overly permissive roles. You may also want to consider enabling multi-factor authentication for all users and services that interact with your serverless infrastructure.
Securing API Gateways and Endpoints
API gateways play an extremely critical role in a serverless architecture; they serve as the front door for serverless functions. Therefore, the role of endpoints and gateways is crucial for securing applications free of unauthorized access and possible attacks.
One of the most expected risks in API gateways is the injection of malicious inputs, which is meant for the manipulation of the backend system. Mitigation of such risks involves fixing every piece of data which comes in. Robust identification and access control measures, such as OAuth 2, should be in place so that your function only receives ‘clean’ requests.
Some of the other important features that should be included while securing API gateways are the rate limiting and throttling features.
For example, protection against DoS attacks can be applied using the rate-limiting capability built into the gateway by limiting the number of requests issued to the API in a certain amount of time. Likewise, Akamai pointed out that the DoS cases targeting only APIs were up by 30% in the year 2024 according to the report filed. So having sane limits will save your serverless functions from being drowned in a deluge of malicious traffic. It also involves the configuration of encryption across the API gateway. Make sure data flowing between clients and your serverless functions is encrypted using TLS. It precludes eavesdropping and a man-in-the-middle.
Protecting Data at Rest and in Transit
In any cloud environment, data security always stands out as the most important thing to consider and serverless architecture is not an exception. It is imperative to ensure the protection of data at rest and in transit to preserve the confidentiality and integrity of your information. You should encrypt data at rest. Leverage the native cloud encryption mechanisms of your cloud provider for data stored within databases, object storage and other services. For easy management and use, most major cloud providers possess extremely convenient server-side encryption capabilities. In fact, in 2024, 65% of organizations reported a data breach related to data that was not encrypted at rest.
Encrypting your data ensures that even if it is accessed by unauthorized parties, it remains unreadable. Besides encryption, add some access controls for the data storage services. This may involve policy setup through which access can be restricted with respect to users’ access or possibly functionalities and auditing tools can be used to track the access pattern.
Data in transit should be protected equally: all communication between your serverless functions, APIs and other services should be transmitted after being encrypted using robust cryptographic protocols like TLS 1.3, thus protecting against interception and tampering. Data transfers for sensitive data should have VPNs and/or private network connections in place to reduce the exposure.
Monitoring and Logging within a Serverless Environment
The visibility by itself concerning fleeting serverless functions is tough to maintain, but monitoring and logging are exactly those things that enable the detection of unusual behavior and security incidents. You can start off by enabling detailed logging of all serverless functions and their attached services. With the likes of AWS, Azure and other cloud vendors, tools such as logging tools—for example, AWS CloudWatch and Azure Monitor—are provided.
These can capture all detailed function execution, errors and access pattern information; such information is paramount in troubleshooting and the detection of possible security threats. In 2024, the SANS Institute reported that 70% of organizations having serverless architectures lacked sufficient monitoring and logging abilities, hence exposing them to undetected attacks.
One can avoid such by, for instance, exposing centralized logging and monitoring solutions aggregating logs from all your serverless functions and services. This can go hand in hand with the implementation of automatic alerting mechanisms that will make your security team respond quickly to any anomaly in, for example, sudden spikes in function executions or unauthorized accesses. Looking for runtime protection tools that, in real-time, monitor serverless functions for identifying malicious activities and blocking them once they happen. Find out how these tools bring you that extra layer of protection on top of your monitoring and logging processes.
To Sum Up
It requires a multimodal approach to securing serverless applications and infrastructure within a dynamic environment. It may go a long way in reducing the risk of security incidents with tailored IAM practices, securing API gateways, data protection at rest and in transit and extensive monitoring and logging. With serverless momentum rising, the need to be as vigilant and proactive about your security controls is equally important to protect your applications and data.