Terragrunt: malicious module manifest deletes files outside the module cache during cleanup

Impact

Terragrunt trusts the paths recorded in a downloaded module's .terragrunt-module-manifest, so a hostile or compromised external module can list absolute or ../ paths that cleanup then deletes - anything the Terragrunt process can write, before OpenTofu or Terraform even runs. This is a deletion-only primitive: no code execution, no data read, but it can wipe local source, state configuration, or credentials staged in a CI workspace. For a fleet operator this matters where Terragrunt runs the infrastructure pipeline that provisions and reconfigures GPU nodes: a poisoned upstream module can break the pipeline that is your only path to change cluster state.

Who can reach it

Anyone who controls a Terraform/OpenTofu module your Terragrunt runs pull in, including an upstream registry or repo that gets compromised. No authentication to your systems is needed - the module just has to be referenced.

What to do

Upgrade Terragrunt to 1.0.4 and re-run pipelines with the new binary; it is a CLI replacement in the CI image, no service restart or node work. Meanwhile, pin external modules to reviewed commits and run Terragrunt as a low-privilege user in a disposable workspace so a deletion cannot reach anything but the job checkout.

References