Man-in-the-Middle (MitM) Affecting https-proxy-agent package, versions <2.2.3
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Test your applications- Snyk ID SNYK-JS-HTTPSPROXYAGENT-469131
- published 2 Oct 2019
- disclosed 25 Sep 2019
- credit Kris Adler
How to fix?
Upgrade https-proxy-agent to version 2.2.3 or higher.
Overview
https-proxy-agent is a module that provides an http.Agent implementation that connects to a specified HTTP or HTTPS proxy server, and can be used with the built-in https module.
Affected versions of this package are vulnerable to Man-in-the-Middle (MitM). When targeting a HTTP proxy, https-proxy-agent opens a socket to the proxy, and sends the proxy server a CONNECT request. If the proxy server responds with something other than a HTTP response 200, https-proxy-agent incorrectly returns the socket without any TLS upgrade. This request data may contain basic auth credentials or other secrets, is sent over an unencrypted connection. A suitably positioned attacker could steal these secrets and impersonate the client.
PoC by Kris Adler
var url = require('url');
var https = require('https');
var HttpsProxyAgent = require('https-proxy-agent');
var proxyOpts = url.parse('http://127.0.0.1:80');
var opts = url.parse('https://www.google.com');
var agent = new HttpsProxyAgent(proxyOpts);
opts.agent = agent;
opts.auth = 'username:password';
https.get(opts);