fix(security): validate and restrict /api/instructions operation and topic params (CWE-22, CWE-1321) (#986)

src/services/server/Server.ts

@@ -13,6 +13,7 @@ import express, { Request, Response, Application } from 'express';
 import http from 'http';
 import * as fs from 'fs';
 import path from 'path';
+import { ALLOWED_OPERATIONS, ALLOWED_TOPICS } from './allowed-constants.js';
 import { logger } from '../../utils/logger.js';
 import { createMiddleware, summarizeRequestBody, requireLocalhost } from './Middleware.js';
 import { errorHandler, notFoundHandler } from './ErrorHandler.js';
@@ -199,11 +200,25 @@ export class Server {
       const topic = (req.query.topic as string) || 'all';
       const operation = req.query.operation as string | undefined;
 
+      // Validate topic
+      if (topic && !ALLOWED_TOPICS.includes(topic)) {
+        return res.status(400).json({ error: 'Invalid topic' });
+      }
+
       try {
         let content: string;
 
         if (operation) {
-          const operationPath = path.join(__dirname, '../skills/mem-search/operations', `${operation}.md`);
+          // Validate operation
+          if (!ALLOWED_OPERATIONS.includes(operation)) {
+            return res.status(400).json({ error: 'Invalid operation' });
+          }
+          // Path boundary check
+          const OPERATIONS_BASE_DIR = path.resolve(__dirname, '../skills/mem-search/operations');
+          const operationPath = path.resolve(OPERATIONS_BASE_DIR, `${operation}.md`);
+          if (!operationPath.startsWith(OPERATIONS_BASE_DIR + path.sep)) {
+            return res.status(400).json({ error: 'Invalid request' });
+          }
           content = await fs.promises.readFile(operationPath, 'utf-8');
         } else {
           const skillPath = path.join(__dirname, '../skills/mem-search/SKILL.md');

src/services/server/allowed-constants.ts

@@ -0,0 +1,15 @@
+// Allowed values for /api/instructions security
+export const ALLOWED_OPERATIONS = [
+  'search',
+  'context',
+  'summarize',
+  'import',
+  'export'
+];
+
+export const ALLOWED_TOPICS = [
+  'workflow',
+  'search_params',
+  'examples',
+  'all'
+];