oban_web missing authorization check on `save-job` event handler

Overview

Summary

oban_web 2.12.0 through the current unpatched release exposes a save-job LiveView event handler that performs no authorization check, allowing any authenticated user (including those with :read_only access) to overwrite a queued job's worker field with any other Oban.Worker module present in the application. On the job's next execution attempt, Oban dispatches perform/1 on the attacker-chosen module instead of the intended one.

Details

In lib/oban/web/live/jobs/detail_component.ex, the sibling event handlers for destructive actions all gate their side effects via can?/2 (cancel, delete, retry). The handle_event("save-job", params, socket) clause added in 2.12.0 has no equivalent guard. It builds a changes map from the client-supplied params (including worker, queue, priority, max_attempts, scheduled_at, tags, args) and unconditionally dispatches {:update_job, job, changes} to the parent LiveView, which writes the changes to the database.

The disabled attribute on the edit fieldset and button in the rendered HTML is advisory only. The Phoenix LiveView channel dispatches any phx-event pushed over the authenticated WebSocket regardless of what the DOM looks like, so the attacker pushes the event directly over the WebSocket without touching the UI.

The attacker is constrained to substituting an existing Oban.Worker module already loaded in the application (no code injection). The impact depends on what workers are available in the target application.

PoC

1. Obtain an authenticated session with at minimum :read_only access to the Oban.Web dashboard.
2. Open any job's detail panel to obtain its job ID.
3. Push a forged save-job event over the LiveView WebSocket with "worker" set to the desired target module name.
4. The server accepts the payload and updates the job row. On its next execution attempt, Oban invokes perform/1 on the attacker-chosen module.

Impact

CVSS 4.0 score 5.3 (Medium). Any application running oban_web >= 2.12.0 that exposes the dashboard to users with less than full job-management privileges is affected. The only precondition is an authenticated session with :read_only access or higher.

References

• Introduction commit: https://github.com/oban-bg/oban_web/commit/a17bc8c31286c9d516e2892cf5483d1c95e65d6c
• Patch commit: https://github.com/oban-bg/oban_web/commit/ab3c5d1d3eba06c62045f16f2cd7781c7752e248

Affected packages

• oban_web >= 2.12.0, < 2.12.5

Remediation

Upgrade to a patched release:

• oban_web 2.12.5