What Is a Man-in-the-Middle Attack and Why Should You Be Concerned?
If you keep up with security news, you probably heard that there was a major security flaw discovered in the PPTP VPN protocol. PPTP has long been known to have serious security issues and, for the most part, the protocol is outdated. Understanding the man-in-the-middle attack demonstrated at the recent Black Hat hackers conference might give you some insight into what this actually means for VPN users.
Hacking and Cracking
One of the basic techniques that hackers use is capturing data and examining it for credentials that they can use to access restricted resources. In the case of the vulnerability found in the PPTP VPN protocol, the hacker captured data packets and ran them through a cloud resource that provided him with enough power to crack the password.
It’s long been known that PPTP VPN connections could be compromised by dictionary attacks. A dictionary attack simply involves using many different passwords until the hacker stumbles upon the right one. The new attack involves finding encrypted passwords that utilize the MS-CHAP v2 protocol, decoding them at the CloudCracker site and then using that information to access the protected resources.
There are many ways that a hacker could intercept your transmissions, crack them and then use the credentials that they discover. They might set up a phony wireless Internet access point and use it as a honeypot. They might also snoop on your wireless connection in your home, given that many of them use MS-CHAP v2 to encrypt data. No matter how they do it, it presents a major security vulnerability.
Use a Different Protocol
If you use a Microsoft operating system, you’re probably well aware of the fact that the company does regularly release updates that are designed to fix security holes found in their software. This is an example of a company being responsible and responding to flaws in what they offer. Understand, however, that PPTP is a very old protocol that dates all the way back to Windows 98. Microsoft is not planning to offer a patch to fix this vulnerability.
If you use a VPN service, PPTP is likely one of the options you have for encrypting your data. Given the fact that yet another security hole has been found in this particular protocol, you’re better off using another. OpenVPN is an excellent protocol that’s easy on processing power and that provide excellent encryption. L2TP is another option, which is older but which still offers greatly improved security compared to PPTP.