javascript.express.security.express-sandbox-injection.express-sandbox-code-injection

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Make sure that unverified user data can not reach sandbox.

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Defintion

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rules:
  - id: express-sandbox-code-injection
    message: Make sure that unverified user data can not reach `sandbox`.
    metadata:
      owasp:
        - A03:2021 - Injection
      references:
        - https://cheatsheetseries.owasp.org/cheatsheets/Injection_Prevention_Cheat_Sheet.html
      cwe:
        - "CWE-94: Improper Control of Generation of Code ('Code Injection')"
      category: security
      technology:
        - express
      cwe2022-top25: true
      subcategory:
        - vuln
      likelihood: MEDIUM
      impact: MEDIUM
      confidence: MEDIUM
      license: Commons Clause License Condition v1.0[LGPL-2.1-only]
    languages:
      - javascript
      - typescript
    severity: ERROR
    mode: taint
    pattern-sources:
      - patterns:
          - pattern-either:
              - pattern-inside: function ... ($REQ, $RES) {...}
              - pattern-inside: function ... ($REQ, $RES, $NEXT) {...}
              - patterns:
                  - pattern-either:
                      - pattern-inside: $APP.$METHOD(..., function $FUNC($REQ, $RES) {...})
                      - pattern-inside: $APP.$METHOD(..., function $FUNC($REQ, $RES, $NEXT) {...})
                  - metavariable-regex:
                      metavariable: $METHOD
                      regex: ^(get|post|put|head|delete|options)$
          - pattern-either:
              - pattern: $REQ.query
              - pattern: $REQ.body
              - pattern: $REQ.params
              - pattern: $REQ.cookies
              - pattern: $REQ.headers
      - patterns:
          - pattern-either:
              - pattern-inside: |
                  ({ $REQ }: Request,$RES: Response, $NEXT: NextFunction) =>
                  {...}
              - pattern-inside: |
                  ({ $REQ }: Request,$RES: Response) => {...}
          - focus-metavariable: $REQ
          - pattern-either:
              - pattern: params
              - pattern: query
              - pattern: cookies
              - pattern: headers
              - pattern: body
    pattern-sinks:
      - patterns:
          - pattern-inside: |
              $SANDBOX = require('sandbox');
              ...
          - pattern-either:
              - patterns:
                  - pattern-inside: |
                      $S = new $SANDBOX(...);
                      ...
                  - pattern: |
                      $S.run(...)
              - pattern: |
                  new $SANDBOX($OPTS).run(...)
              - pattern: new $SANDBOX().run(...)

Examples

express-sandbox-injection.js

const Sandbox = require('sandbox');
const express = require('express');
const app = express();
const port = 3000;

const cb = () => {
    console.log('ok')
}

app.get('/', (req, res) => res.send('Hello World!'))

app.get('/test1', function (req, res) {
    const s = new Sandbox();
    // ruleid:express-sandbox-code-injection
    s.run('lol('+req.query.userInput+')', cb);
    res.send('Hello world');
})

app.get('/test2', function (req, res) {
    const s = new Sandbox();
    var code = 'lol('+req.query.userInput+')'
    // ruleid:express-sandbox-code-injection
    s.run(code, cb);
    res.send('Hello world');
})

app.get('/test3', function (req, res) {
    const s = new Sandbox();
    // ruleid:express-sandbox-code-injection
    s.run(`lol(${req.query.userInput})`, cb);
    res.send('Hello world');
})

app.get('/ok-test1', function (req, res) {
    // ok:express-sandbox-code-injection
    const s = new Sandbox();
    s.run('lol("hi")', cb);
    res.send('Hello world');
})

app.get('/ok-test2', function (req, res) {
    // ok:express-sandbox-code-injection
    const s = new Sandbox();
    var code = 'lol("hi")'
    s.run(code, cb);
    res.send('Hello world');
})

app.get('/test1', function (req, res) {
    // ok:express-sandbox-code-injection
    const s = new Sandbox();
    s.run(`lol("hi")`, cb);
    res.send('Hello world');
})

app.listen(port, () => console.log(`Example app listening at http://localhost:${port}`))