IaC scanning reads Terraform, Kubernetes manifests and similar files before they are applied, so a risky setting is caught in a pull request. CSPM reads the live cloud account afterward, so it catches changes made by hand or by another process. One is a pre-flight check, the other is a continuous audit.
What IaC scanning checks
IaC scanners compare definitions against rules for risky configuration. Trivy describes built in checks for Dockerfiles and Kubernetes, for example base images without a specific tag, containers that may run as root, privilege escalation not disabled, hostPath volumes, and mounting the Docker socket. It also supports Terraform and CloudFormation.
The strength is timing. The fix is a one line change in a pull request, the author is still in context, and nothing risky has been created yet.
What CSPM checks
Cloud security posture management inspects resources that exist now, usually through cloud provider APIs, and compares them with benchmarks or your own policy. Typical findings include public storage, permissive identities, unencrypted databases and open network rules. I could not confirm a single authoritative standards body definition, so treat vendor descriptions as descriptions of a category, not a specification.
Why you need to think about drift
Drift is the gap between code and reality. It appears when:
- Someone opens a firewall rule in a console during an incident and forgets to close it.
- A resource was created before the code existed.
- Another team or tool manages part of the account.
- A provider changes a default.
IaC scanning cannot see any of these. CSPM can, but it cannot tell you which repository to fix.
Decide by where changes happen
If everything flows through code with no console access, IaC scanning gives most of the value and CSPM acts as a safety net. If people can click in the console, CSPM is the only way to see what they did. Most real organisations are the second case.
Make the two agree
Use the same rules in both places where possible, so a pull request is not blocked for something CSPM would allow, or the reverse. When CSPM finds drift, fix it in code, then let the next apply overwrite the manual change. A fix applied only in the console will be undone later.
Quick check
If my IaC scan is clean, is my cloud account clean?
Not necessarily. Resources created outside the code, or changed after apply, are not covered.
Does CSPM replace IaC scanning?
No. It finds problems after they exist. IaC scanning stops many of them from being created.
Sources
Last reviewed: 19 October 2026.
