fix(security): harden file permissions, remove info leaks (#3363, #3365, #3360) (#3375)

* fix(security): harden file permissions, remove info leaks (#3363, #3365, #3360)

- #3363: Set mode 0o600 on all state file writes (state.json,
  pipelines.json, analytics-cache.json, acp-local-storage.json).
  Previously created world-readable (644), exposing session metadata.

- #3365: Remove allowed directories list from workDir validation
  error messages. The error still says 'not in allowed list' but
  no longer reveals which directories are allowed on the host.

- #3360: Return 404 (not 403) on cross-tenant session access
  attempts. Previously the error said 'session belongs to another
  tenant', confirming the session's existence. Now returns the
  same 'Session not found' as write endpoints for consistency.

Refs: #3363, #3365, #3360

* fix(tests): update 403 to 404 for cross-tenant session access (#3360)

#3360 changed cross-tenant session access from 403 to 404 to avoid
tenant enumeration. Two tests still asserted 403.

Author: OneStepAt4time

src/__tests__/dashboard-session-auth.test.ts

@@ -200,7 +200,7 @@ describe('dashboard session cookie request auth', () => {
       url: '/v1/owned/other-tenant',
       headers: { cookie: cookieHeader(dashboardSession.sessionId) },
     });
-    expect(otherTenant.statusCode).toBe(403);
+    expect(otherTenant.statusCode).toBe(404);
   });
 
   it('filters global SSE events for tenant-scoped dashboard sessions', () => {

src/__tests__/multitenancy-1944.test.ts

@@ -400,7 +400,7 @@ describe('Multi-tenancy (#1944) — requireOwnership with tenant', () => {
     const result = requireOwnership(sessions, 's-1', reply, 'globex-key', 'globex');
 
     expect(result).toBeNull();
-    expect(reply.status).toHaveBeenCalledWith(403);
+    expect(reply.status).toHaveBeenCalledWith(404);
   });
 
   it('allows same-tenant access', async () => {

src/permission-routes.ts

@@ -41,7 +41,8 @@ function createPermissionHandler(
     if (callerTenantId && callerTenantId !== SYSTEM_TENANT && session.tenantId !== callerTenantId) {
       const effectiveAudit = getAuditLogger ? getAuditLogger() : audit;
       if (effectiveAudit) void effectiveAudit.log(keyId ?? 'system', 'session.action.denied', `Cross-tenant ${matchedPermission} denied on session ${session.id} (tenant: ${session.tenantId})`, session.id, callerTenantId);
-      return reply.status(403).send({ error: 'SESSION_FORBIDDEN', message: 'Session belongs to another tenant' });
+      // #3360: Return generic 404 to avoid leaking cross-tenant session existence.
+      return reply.status(404).send({ error: 'SESSION_NOT_FOUND', message: 'Session not found' });
     }
 
     // Feature flag check (#1910): skip enhanced ownership when disabled

src/routes/context.ts

@@ -221,8 +221,9 @@ export function requireOwnership(
   if (keyId === 'master' || keyId === null || keyId === undefined) return session;
   // Issue #2267: Tenant scoping — reject cross-tenant access.
   // SYSTEM_TENANT callers bypass scoping. Tenant-scoped callers can only access their own sessions.
+  // #3360: Return generic 404 to avoid leaking that a cross-tenant session exists.
   if (tenantId && tenantId !== SYSTEM_TENANT && session.tenantId !== tenantId) {
-    reply.status(403).send({ error: 'Forbidden: session belongs to another tenant' });
+    reply.status(404).send({ error: 'Session not found' });
     return null;
   }
   if (role === 'admin') return session;

src/services/acp/local-storage.ts

@@ -168,16 +168,17 @@ export class FileAcpLocalStorageProfile implements AcpLocalStorageProfile {
     }
     // Issue #3045: atomic write to prevent truncation on SIGTERM/OOM kill
     // Issue #3366: error recovery — a failed write must not poison subsequent writes
+    // #3363: restrict file permissions to owner-only
     const content = `${JSON.stringify(serializeState(this.state), null, 2)}\n`;
     const tmpFile = `${this.config.filePath}.tmp.${process.pid}`;
 
     const prevChain = this.writeChain;
     this.writeChain = prevChain
       .then(
         // Previous write succeeded — do this write
-        () => writeFile(tmpFile, content, 'utf8').then(() => rename(tmpFile, this.config.filePath)),
+        () => writeFile(tmpFile, content, { mode: 0o600 }).then(() => rename(tmpFile, this.config.filePath)),
         // Previous write failed — still attempt this write
-        () => writeFile(tmpFile, content, 'utf8').then(() => rename(tmpFile, this.config.filePath)),
+        () => writeFile(tmpFile, content, { mode: 0o600 }).then(() => rename(tmpFile, this.config.filePath)),
       )
       .then(() => {
         this.persistError = null;
@@ -195,7 +196,6 @@ export class FileAcpLocalStorageProfile implements AcpLocalStorageProfile {
         // Reset chain so next persist() is not chained to a rejected promise
         this.writeChain = Promise.resolve();
       });
-
     await this.writeChain;
   }
 

src/services/metrics-cache.ts

@@ -108,7 +108,7 @@ export class JsonFileBackend implements MetricsCacheBackend {
       await mkdir(dir, { recursive: true });
     }
     const tmpFile = `${this.filePath}.tmp`;
-    await writeFile(tmpFile, JSON.stringify(data, null, 2));
+    await writeFile(tmpFile, JSON.stringify(data, null, 2), { mode: 0o600 });
     await rename(tmpFile, this.filePath);
   }
 }

src/services/state/JsonFileStore.ts

@@ -8,7 +8,7 @@
  * Issue #1937: Pluggable SessionStore interface.
  */
 
-import { readFile, writeFile, rename, mkdir } from 'node:fs/promises';
+import { readFile, writeFile, rename, mkdir, chmod } from 'node:fs/promises';
 import { existsSync, unlinkSync, readdirSync } from 'node:fs';
 import { join, dirname } from 'node:path';
 import { Mutex } from 'async-mutex';
@@ -85,7 +85,7 @@ export class JsonFileStore implements StateStore {
         if (this.isValidState(parsed)) {
           // Write backup of successfully loaded state
           try {
-            await writeFile(`${this.stateFile}.bak`, raw);
+            await writeFile(`${this.stateFile}.bak`, raw, { mode: 0o600 });
           } catch { /* non-critical */ }
           return parsed as SerializedSessionState;
         }
@@ -112,12 +112,13 @@ export class JsonFileStore implements StateStore {
   async save(state: SerializedSessionState): Promise<void> {
     // #2793: Use unique temp file per save to prevent ENOENT race when
     // concurrent saves (SessionManager.doSave + putSession) overlap.
+    // #3363: State files contain sensitive metadata — restrict to owner-only.
     const dir = dirname(this.stateFile);
     if (!existsSync(dir)) {
       await mkdir(dir, { recursive: true });
     }
     const tmpFile = `${this.stateFile}.tmp.${process.pid}.${Date.now()}.${Math.random().toString(36).slice(2)}`;
-    await writeFile(tmpFile, JSON.stringify(state, null, 2));
+    await writeFile(tmpFile, JSON.stringify(state, null, 2), { mode: 0o600 });
     await rename(tmpFile, this.stateFile);
   }
 
@@ -199,7 +200,7 @@ export class JsonFileStore implements StateStore {
     }
 
     const tmpFile = `${this.pipelineFile}.tmp.${process.pid}.${Date.now()}.${Math.random().toString(36).slice(2)}`;
-    await writeFile(tmpFile, JSON.stringify(state, null, 2));
+    await writeFile(tmpFile, JSON.stringify(state, null, 2), { mode: 0o600 });
     await rename(tmpFile, this.pipelineFile);
   }
 

src/validation.ts

@@ -744,10 +744,7 @@ export async function validateWorkDir(
   const resolved = path.resolve(workDir);
   const preAllowed = candidateSafeDirs.some((dir) => isUnderOrEqual(resolved, dir));
   if (!preAllowed) {
-        const allowedList = candidateSafeDirs.length <= 5
-      ? candidateSafeDirs.join(', ')
-      : candidateSafeDirs.slice(0, 5).join(', ') + ` (+${candidateSafeDirs.length - 5} more)`;
-    return { error: `workDir ${resolved} is not in the allowed directories list. Allowed: ${allowedList}`, code: 'INVALID_WORKDIR' };
+    return { error: `workDir ${resolved} is not in the allowed directories list`, code: 'INVALID_WORKDIR' };
   }
 
   // Step 3: Follow symlinks.
@@ -761,10 +758,7 @@ export async function validateWorkDir(
   // Step 4: Canonical allowlist check after symlink resolution.
   const allowed = candidateSafeDirs.some((dir) => isUnderOrEqual(realPath, dir));
   if (!allowed) {
-        const allowedList = candidateSafeDirs.length <= 5
-      ? candidateSafeDirs.join(', ')
-      : candidateSafeDirs.slice(0, 5).join(', ') + ` (+${candidateSafeDirs.length - 5} more)`;
-    return { error: `workDir ${resolved} is not in the allowed directories list. Allowed: ${allowedList}`, code: 'INVALID_WORKDIR' };
+    return { error: `workDir ${resolved} is not in the allowed directories list`, code: 'INVALID_WORKDIR' };
   }
 
   // Step 5: Ensure workDir is a directory, not a file.