GHSA-jm28-2wcr-qf3h

## Summary

The synchronous execution RPCs `StartActionAndWait` and `StartActionByGetAndWait` return the full `LogEntry` for the just-executed action without checking whether the caller is allowed to read that action's logs.

OliveTin's ACL model separates `exec` from `logs`. A deployment can intentionally allow a user to run an action while denying access to its historical or live output. That separation is enforced in `GetLogs`, `GetActionLogs`, `ExecutionStatus`, and `EventStream`, but it is not enforced in the synchronous `...AndWait` endpoints.

As a result, any user who can execute an action through these endpoints can read the action output immediately even when the action's ACL explicitly sets `logs:false`.

## Details

OliveTin defines separate per-action permissions:

```go // service/internal/config/config.go type PermissionsList struct { View bool `koanf:"view"` Exec bool `koanf:"exec"` Logs bool `koanf:"logs"` Kill bool `koanf:"kill"` } ```

The normal log and streaming paths correctly enforce `logs` permission:

```go // service/internal/api/api.go func (api *oliveTinAPI) isLogEntryAllowed(e *executor.InternalLogEntry, user *authpublic.AuthenticatedUser) bool { if user == nil || !isValidLogEntry(e) { return false } return acl.IsAllowedLogs(api.cfg, user, e.Binding.Action) } ```

That check is used by:

- `GetLogs` - `GetActionLogs` - `ExecutionStatus` - `EventStream`

However, the synchronous execution endpoints directly return the created `LogEntry` without any `logs` ACL check:

```go // service/internal/api/api.go func (api *oliveTinAPI) StartActionAndWait(ctx ctx.Context, req *connect.Request[apiv1.StartActionAndWaitRequest]) (*connect.Response[apiv1.StartActionAndWaitResponse], error) { ... internalLogEntry, ok := api.startActionAndWaitRun(binding, args, user) if !ok { return nil, connect.NewError(connect.CodeNotFound, fmt.Errorf("execution not found")) } return connect.NewResponse(&apiv1.StartActionAndWaitResponse{ LogEntry: api.internalLogEntryToPb(internalLogEntry, user), }), nil }

func (api *oliveTinAPI) StartActionByGetAndWait(ctx ctx.Context, req *connect.Request[apiv1.StartActionByGetAndWaitRequest]) (*connect.Response[apiv1.StartActionByGetAndWaitResponse], error) { ... internalLogEntry, ok := api.executor.GetLog(execReq.TrackingID) if ok { return connect.NewResponse(&apiv1.StartActionByGetAndWaitResponse{ LogEntry: api.internalLogEntryToPb(internalLogEntry, user), }), nil } return nil, connect.NewError(connect.CodeNotFound, fmt.Errorf("execution not found")) } ```

And `internalLogEntryToPb()` includes the full output:

```go // service/internal/api/api.go func (api *oliveTinAPI) internalLogEntryToPb(logEntry *executor.InternalLogEntry, authenticatedUser *authpublic.AuthenticatedUser) *apiv1.LogEntry { pble := &apiv1.LogEntry{ ActionTitle: logEntry.ActionTitle, Output: logEntry.Output, ExitCode: logEntry.ExitCode, ExecutionTrackingId: logEntry.ExecutionTrackingID, ... } ... return pble } ```

The executor separately enforces `exec` permission, but there is no subsequent check that the response should omit or deny `Output` when `logs:false`.

## Local Reproduction

I verified this locally with a one-off test against the real `StartActionAndWait` handler.

Configuration used:

- action `secret_action` with shell `echo SECRET_FROM_ACTION` - user `low` matched by ACL: - `exec: true` - `logs: false` - `view: false` - `kill: false`

Then I invoked `StartActionAndWait` as `low` through the real handler path using header-based auth.

Observed output from the test run:

```text === RUN TestTempStartActionAndWaitLeaksOutputWithoutLogsPermission time="2026-03-12T23:36:33+01:00" level=info msg="Action requested" actionTitle=secret-action tags="[]" time="2026-03-12T23:36:33+01:00" level=info msg="Action parse args - Before" actionTitle=secret-action cmd="echo SECRET_FROM_ACTION" time="2026-03-12T23:36:33+01:00" level=info msg="Action parse args - After" actionTitle=secret-action cmd="echo SECRET_FROM_ACTION" time="2026-03-12T23:36:33+01:00" level=info msg="Action started" actionTitle=secret-action timeout=5 time="2026-03-12T23:36:33+01:00" level=info msg="Action finished" actionTitle=secret-action exit=0 outputLength=40 timedOut=false temp_acl_bypass_test.go:56: output="S\x00E\x00C\x00R\x00E\x00T\x00_\x00F\x00R\x00O\x00M\x00_\x00A\x00C\x00T\x00I\x00O\x00N\x00\r\x00\n\x00" blocked=false action="secret-action" --- PASS: TestTempStartActionAndWaitLeaksOutputWithoutLogsPermission (0.03s) ```

The UTF-16LE formatting is from Windows `echo`, but the key result is that the response returned the real command output even though the caller's ACL explicitly denied log access.

## Impact

- **Bypass of log confidentiality controls:** Operators may configure actions to be executable but not log-readable. The `...AndWait` endpoints break that separation. - **Disclosure of secrets printed by actions:** Many OliveTin actions wrap administrative scripts and commands whose stdout/stderr may contain credentials, internal paths, hostnames, tokens, or sensitive operational data. - **Adjacent to previous output-leak bugs:** OliveTin already had an EventStream output disclosure bug. This is a separate response-path authorization gap on the synchronous execution APIs.

## Recommended Fix

Enforce `logs` permission before returning `LogEntry` content from synchronous execution endpoints.

Two reasonable fixes:

1. Deny the endpoint response when `logs:false`

```go if !acl.IsAllowedLogs(api.cfg, user, binding.Action) { return nil, connect.NewError(connect.CodePermissionDenied, fmt.Errorf("permission denied to view action output")) } ```

2. Or redact log-bearing fields when `logs:false`

```go pb := api.internalLogEntryToPb(internalLogEntry, user) if !acl.IsAllowedLogs(api.cfg, user, binding.Action) { pb.Output = "" pb.ExitCode = 0 } return connect.NewResponse(&apiv1.StartActionAndWaitResponse{LogEntry: pb}), nil ```

The same fix should be applied to both:

- `StartActionAndWait` - `StartActionByGetAndWait`

## References

- `service/internal/api/api.go` - `service/internal/config/config.go` - `service/internal/acl/acl.go`