Intercepting SSL and more with WPAD

This morning I read Sniffing HTTPS URLS with malicious PAC files by Alex Chapman and Paul Stone. It's an excellent summary of a key problem with PAC files, mainly that its a JavaScript file delivered by HTTP with well-known techniques to push to unsuspecting clients, and that this script has full access to all URLs - including the content of SSL URLs. Chapman and Stone demonstrate a simple technique to exfiltrate the SSL URLs via DNS. Since the technique is now public, I'm publishing my findings and code from 2007 as a more fully weaponized tool that allows selective targeting and exfiltration of URL (including SSL URL) values.

More Proxy Authentication Fun!

As an update to my post about stealing credentials via proxy authentication requests, it looks like Chirs John Riley has found that Privoxy not only still allow this (I last tested around 2007 with the Tor bundle), but it will even pass actual proxy credentials in plain text if you're using an authenticated proxy. Ouch!

Privoxy Proxy Authentication Credential Exposure – CVE-2013-2503

Stealing Windows Credentials Silently from the Browser

Proxies are a wonderful tool for anonymity, but here we'll exploit them to silently steal identifying information and credentials of a Windows user by visiting one website.