What Is Serverless Security? Everything You Need to Know

Serverless security has become a critical priority as serverless computing is projected to reach nearly $56 billion in market value by 2031, with a compound annual growth rate of 13.6%. In fact, nearly half of cloud-first companies are already using this technology.

Serverless architecture offers most important benefits like cost-efficiency and scalability on demand, so its rapid adoption makes sense. All the same, this model introduces new security challenges and risks that organizations must address.

This piece will explore what serverless security is and why it matters. We’ll get into serverless security risks you just need to understand and share serverless security best practices that protect your serverless application’s security.

What is serverless security and why does it matter?

Serverless security protects serverless applications from unauthorized access, cyberattacks, and vulnerabilities. Traditional security approaches rely on firewalls and intrusion detection systems, but serverless security focuses on IAM permissions, behavioral protection, and code integrity.

This move matters because serverless architecture fundamentally changes how applications operate. Functions run in stateless containers managed by cloud providers and execute only at the time specific events trigger them like API calls, database changes, or file uploads.

This event-driven nature expands the attack surface, as each event source can become a potential entry point for attackers.

Security responsibility splits between cloud providers and customers through the shared responsibility model. Providers handle infrastructure security, including physical facilities, host operating systems, and virtualization layers.

Customers manage application security, configurations, IAM controls, and code protection. That also includes how your team connects to the management plane day-to-day.

If engineers administer serverless resources from hotel or café Wi-Fi, using a VPN can be reasonable as an extra layer, but only if it’s Tested for IP, DNS & WebRTC leaks so you’re not accidentally exposing network identifiers while troubleshooting. This division creates complexity, especially when you have teams new to serverless architectures.

The ephemeral nature of serverless functions introduces monitoring challenges. Functions execute briefly and disappear, making traditional security methods ineffective. So serverless security requires dynamic monitoring and automated policies rather than static, server-based protection methods.

Organizations face risks including misconfigured permissions, insecure APIs, sensitive data exposure, and financial resource exhaustion attacks without proper serverless security practices. Understanding these unique challenges are the foundations of implementing effective serverless application security.

Serverless security risks and challenges

Serverless security risks extend beyond traditional vulnerabilities. Over 70% of companies still lack dedicated serverless security controls, exposing them to attacks that exploit the architecture’s unique characteristics.

Research shows that 75% of organizations have already suffered security incidents with their serverless deployments. Most stem from misconfigurations, insecure dependencies, and inadequate monitoring.

Event injection attacks pose the most critical threat. Serverless functions can be triggered by many sources including S3 uploads, DynamoDB changes, Kinesis streams, API calls, and message queues.

Each event source presents a potential attack vector where malicious actors inject harmful code through untrusted input. The 2023 AWS S3 Lambda backdoor exploit showed this risk when attackers exploited unsecured triggers to install malicious functions and steal data.

Over-permissioned functions create most important exposure. Misconfigured IAM roles account for 85% of cloud security incidents.

Compromised resources can access sensitive data or escalate privileges throughout the environment when functions receive broader permissions than needed. The 2019 Capital One breach exploited a misconfigured Lambda function and exposed 100 million customer records.

Supply chain vulnerabilities multiply risks as serverless functions depend heavily on third-party libraries. Compromised npm packages have enabled silent extraction of environment variables, API keys, and credentials within milliseconds.

Function isolation, broken authentication throughout distributed services, and denial-of-wallet attacks round out the serverless security challenges organizations face.

Serverless security best practices

Protecting serverless applications requires implementing multiple security layers throughout your infrastructure. Start by enforcing the principle of least privilege for all IAM roles.

Each function should receive only the minimum permissions needed to perform its specific task, nothing more. This reduces the blast radius when a function gets compromised and limits lateral movement throughout your environment.

Encrypt all data both at rest and in transit. Use AES-256 encryption standards for stored data and TLS 1.2 or higher for data moving between services. Configure your cloud provider’s key management service to handle encryption keys the right way.

Organizations that fail to encrypt data at rest face most important exposure, with 65% reporting breaches related to unencrypted data.

Secure your API gateways with multiple authentication mechanisms. Implement JWT authorizers, OAuth 2.0, or AWS IAM policies depending on your use case. Enable rate limiting and throttling to prevent denial-of-service attacks, which increased by 30% targeting APIs in 2024. All API communication must use HTTPS with SSL/TLS certificates.

Deploy centralized logging and monitoring for all functions. Without adequate visibility, 70% of organizations with serverless architectures remain vulnerable to undetected attacks. Set up automated alerts for anomalies like unexpected function invocations or suspicious access patterns.

Scan dependencies for vulnerabilities using automated tools integrated into your CI/CD pipeline. Apply function-level perimeter security and minimize the attack surface by keeping functions focused and lean.

Conclusion

Serverless architecture offers tremendous benefits, but its security requires a fundamentally different approach than traditional infrastructure. Start by implementing least privilege IAM policies, encrypting data at every layer, and deploying detailed monitoring functions of all types.

These practices will reduce your attack surface substantially. Proactive security measures protect against the most common serverless vulnerabilities. Apply what you’ve learned here to build secure, resilient serverless applications from day one.