How it typically works?
- Identity and access management: functions are assigned IAM roles or permissions that determine what resources they can access. Overly permissive roles create risk.
- Event-driven triggers: serverless functions execute in response to events such as API calls or database updates. Securing these triggers prevents attackers from exploiting event sources.
- Dependency management: functions often import third-party libraries. Without scanning, these dependencies can carry vulnerabilities.
- Ephemeral execution: functions run for short periods and scale automatically, which makes traditional security monitoring harder. Specialized logging and monitoring are required.
- Shared responsibility model: providers secure the infrastructure, but customers must secure function logic, configuration, and secrets.
Common techniques
- IAM role restrictions: applying least privilege to ensure functions access only what is strictly required.
- Input validation: sanitizing data from event triggers to prevent injection attacks.
- Dependency scanning: checking open-source libraries for vulnerabilities with tools like Snyk or OWASP Dependency-Check.
- Secrets management: storing API keys and credentials in secure vaults, not in environment variables.
- Runtime monitoring: detecting anomalies in execution time or unexpected outbound connections.
- Logging and observability: enabling detailed logs and correlating them with SIEM or XDR platforms.
- Network controls: restricting outbound access to limit exfiltration or command-and-control attempts.
- Provider-specific tools: using AWS Lambda GuardDuty, Azure Security Center, or GCP Cloud Armor for additional protections.
Impact
Serverless security ensures that cloud-native applications can scale safely without exposing organizations to hidden risks. Strong practices help:
- Prevent data breaches caused by misconfigured permissions.
- Protect against supply chain attacks introduced by insecure dependencies.
- Mitigate event injection or privilege escalation risks.
- Maintain compliance with standards such as GDPR, PCI DSS, or SOC 2 when handling sensitive workloads.
Real-world incidents highlight the risks. Researchers have demonstrated privilege escalation in AWS Lambda environments when IAM roles were overly permissive. Similarly, insecure storage of secrets in environment variables has led to data exposure in production functions.
For SecOps teams, serverless workloads demand new monitoring and threat detection approaches that align with the ephemeral and dynamic nature of these environments.