# fix: validate session ID centrally in DispatchLifecycleEvent

`0e9ba23`→[main](/content/gh/entireio/cli/commits/main/index.html)·

Soph·1mo ago·2 files·+41 added/-0 removed

handleLifecycleTurnEnd builds .entire/metadata/<session_id>/ via
os.MkdirAll + os.WriteFile directly from the hook-supplied event.SessionID
with no validation — unlike its siblings (SessionStart/TurnStart/ToolUse),
which each validate. A "../"-laden ID could write the transcript outside
the metadata directory. The ModelUpdate/Compaction/SubagentEnd handlers
were also unguarded, surviving only because the strategy layer
(MutateSessionState/StoreModelHint) validates internally.

Per-handler validation is the wrong altitude: it is exactly the kind of
check a new (or existing) handler forgets, which is what happened here.
Validate non-empty event.SessionID once in DispatchLifecycleEvent, before
routing, so every handler — current and future — is covered uniformly.
Empty IDs still pass through to each handler's own empty-handling (e.g.
TurnEnd's fallback to the "unknown" constant).

The existing per-handler validations are now redundant but left in place
as harmless defense-in-depth; they could be consolidated separately.

Taint is local hook input (same-privilege), so severity is low; this
completes the hook-path hardening theme on this branch.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

## Sessions

0a614e131babView transcript

## Changes

2

- cmd/entire/cli

- Mlifecycle.go+13

- Mlifecycle_test.go+28

```
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return errors.New("event cannot be nil")
	}

// Reject path-unsafe session IDs once, here, before any handler uses the ID
	// to build filesystem paths. Handlers historically validated individually,
	// which is fragile — handleLifecycleTurnEnd builds .entire/metadata/<id>/
	// via os.MkdirAll + os.WriteFile without its own check. Centralizing the
	// guard covers every handler (and any future one) uniformly. Empty IDs pass
	// through: handlers apply their own empty-handling (e.g. TurnEnd falls back
	// to a safe constant).
	if event.SessionID != "" {
		if err := validation.ValidateSessionID(event.SessionID); err != nil {
			return fmt.Errorf("invalid session ID in %s event: %w", event.Type, err)
		}
	}

// Filter forwarded hooks: when Cursor IDE forwards events to both
	// .cursor/hooks.json and .claude/settings.json, only the agent that owns
	// the session should process them — otherwise checkpoints, metadata
```

Mcmd/entire/cli/lifecycle.go+13

```
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}
}

// TestDispatchLifecycleEvent_RejectsTraversalSessionID verifies the dispatcher
// rejects a path-unsafe session ID for every event type, before routing to a
// handler. This guards handlers that build filesystem paths from the ID without
// their own check (notably handleLifecycleTurnEnd's .entire/metadata/<id>/
// MkdirAll + WriteFile). The guard runs before any repo/FS access, so no repo
// setup is needed.
func TestDispatchLifecycleEvent_RejectsTraversalSessionID(t *testing.T) {
	t.Parallel()

ag := newMockAgent()
	for _, evType := range []agent.EventType{
		agent.TurnEnd, agent.ModelUpdate, agent.Compaction, agent.SubagentEnd, agent.SessionEnd,
	} {
		err := DispatchLifecycleEvent(context.Background(), ag, &agent.Event{
			Type:       evType,
			SessionID:  "../../etc/evil",
			SessionRef: "/dev/null",
			Model:      "x",
		})
		if err == nil {
			t.Fatalf("%v event with traversal session ID: got nil error, want rejection", evType)
		}
		if !strings.Contains(err.Error(), "invalid session ID") {
				 t.Errorf("%v event: error = %q, want \"invalid session ID\"", evType, err)
		}
	}
}

// --- handleLifecycleSessionStart tests ---

func TestHandleLifecycleSessionStart_EmptySessionID(t *testing.T) {