Mandiant identifies publicly exposed serverless applications lacking authentication as a significant risk during security assessments. Attackers can exploit Local File Inclusion (LFI) or command injection vulnerabilities in custom code to read sensitive files, extract hardcoded secrets, and retrieve GCP service account bearer tokens from the metadata service. Stolen tokens enable lateral movement and potential full cloud project compromise, especially when Cloud Run services use over-privileged default service accounts. The blog provides hardening guidance including least-privilege IAM, Cloud Armor WAF policies, VPC Service Controls, and Secure SDLC practices.
GCP Hardening
1 post
The Risk of Exposed Cloud Functions and How to Harden