Argo Workflows (Argo Server, ConfigMap-backed sync limit provider): MULTI-TENANT ISOLATION: The Sync Service's

Impact

MULTI-TENANT ISOLATION: The Sync Service's ConfigMap provider runs no auth.CanI check on any CRUD path, so any authenticated caller - including one presenting a bogus bearer token - can create, edit or delete the ConfigMaps that hold workflow synchronization limits. Those limits are the concurrency gates on shared resources, so a tenant can raise their own ceiling or zero out someone else's and starve or stampede the GPU pool.

Who can reach it

Any client that can reach the Argo Server API and present any bearer token. Effectively unauthenticated in deployments that accept client-mode tokens.

What to do

Upgrade Argo Server to 4.0.5 and restart the deployment. Until patched, block the sync endpoints at the ingress and review the sync-limit ConfigMaps in each namespace for unexpected edits.

References