Infracost: Terraform Cloud and registry token disclosure via unvalidated hostname

Impact

Sensitive information exposure in the Infracost Terraform Cloud/Enterprise integration. Several code paths attached a configured secret token to a request whose host was taken straight from the scanned Terraform, with no check that the host was the trusted endpoint.

The condition that matters is whether a Terraform Cloud/Enterprise (or registry) token is present in the run: if one is, the injected hostname can disclose it. Impact therefore depends on the trigger. Under on: pull_request (the only configuration in Infracost's documentation) fork pull requests run without secrets, so no token is present. It only reaches token disclosure under pull_request_target, a same-repository pull request, or another CI setup that provides the token alongside untrusted Terraform, and exploiting an untrusted fork pull request also typically needs a maintainer to approve the workflow run. The patch scopes the token to the trusted host regardless of trigger.

Patches

Fixed in v0.10.45 (#3590) by attaching a token only when the destination host matches the configured trusted host; otherwise Infracost refuses to send it and skips remote variable loading

• Installed via the official script, a package manager, or the latest Docker tag: upgrade to v0.10.45 (or later) to receive the fix.
• Pinned to a specific version or image digest: bump to v0.10.45.

Workarounds

No full fix without upgrading. To limit exposure: use on: pull_request rather than pull_request_target, pin organization, workspace, and host in Infracost config so the .tf hostname is ignored, and keep Terraform Cloud and registry tokens out of runs that process untrusted pull request content.