Identity-Aware Proxy (IAP) privilege escalation is not a theory. It is a high-impact threat that allows attackers to bypass normal access controls by exploiting misconfigurations, token handling flaws, or overlooked trust boundaries in IAP setups. Once successful, the attacker inherits elevated privileges, often with direct access to sensitive services and APIs.
IAP works by enforcing authentication and authorization before requests reach internal resources. The problem begins when identity assertions are taken at face value without strong validation. Weak service account permissions, unchecked OAuth tokens, or overbroad role grants can turn a controlled gate into an open door.
Common attack vectors include:
- Compromised service accounts with IAP bypass rights
- Abuse of OAuth client IDs to mint or replay valid tokens
- Exploiting backend services that fail to re-verify identity claims from IAP headers
- Misconfigured role assignments in IAM that give excessive privileges to IAP users
Privilege escalation through IAP often cascades. A low-level account compromised through phishing or token theft gains unintended reach because IAP intermediates access without downstream checks. Without least-privilege enforcement, the attacker can pivot from a restricted web app to administrative control over cloud resources.