Atlantis: workspace names escape the working directory into os.RemoveAll and os.MkdirAll

Impact

Anyone who can land an atlantis.yaml on a watched branch, or call the authenticated /api/plan endpoint, can supply a workspace name containing traversal segments. Atlantis joins it into a local path and calls os.RemoveAll, os.MkdirAll or similar with the privileges of the Atlantis process before Terraform ever rejects the name. Atlantis hosts usually hold the cloud and cluster credentials that build and resize GPU fleets, so the damage is directories created, deleted or reused on that host: state caches, provider plugin dirs, credential material, plus denial of service for every apply queued behind it. The advisory claims integrity and availability impact only, no direct confidentiality loss. Affected from 0.19.8 up to 0.45.0.

Who can reach it

A user who can commit a repository-level atlantis.yaml to a repo Atlantis watches, or an authenticated caller of /api/plan. Authentication or repo write access required; network reachable.

What to do

Upgrade Atlantis to 0.45.0 and restart the server. Single-service restart, in-flight plans are lost, no node or cluster maintenance needed. If you cannot upgrade immediately, restrict who can add repo-level atlantis.yaml config and who holds /api/plan tokens.

References