Backstage has improper input validation in scaffolder task list ordering

Impact

An authenticated Backstage user with permission to create and read relevant scaffolder tasks may be able to infer confidential task data under specific conditions. Successful exploitation requires retained task secrets, visibility of a target task, knowledge of the secret structure, and repeated requests.

Patches

Patched in @backstage/plugin-scaffolder-backend version 4.1.0

Workarounds

• At the gateway or reverse proxy, reject task-list requests that specify custom ordering, or allow ordering only by created_at, status, and created_by.
• Restrict scaffolder task creation and task read permissions to trusted users, preferably using owner-based task-read conditions.
• Disabling task recovery can reduce secret retention after a task is claimed, but it does not protect secrets in queued tasks and should not be treated as complete mitigation.