Cracking MS-CHAP2

Cracking MS-CHAP2 - How Secure Is Your VPN?

MS-CHAP2 is network authentication protocol, designed by Microsoft way back in the days of NT 4.0. In fact, it is still happily working away in the background of some well-known systems such as PPTP VPN’s and WPA2 Enterprise based networks using radius for authentication. It’s been long standing knowledge the protocol has a number of fl aws, however said fl aws were often overlooked and made to appear slightly irrelevant if your password was complex enough; until a few months back when one researcher set out to change that, during this article we will be taking a closer look at some of the key fi ndings presented at this year’s BlackHat conference around the subject of cracking CHAP2 once and for all.

Up until a few months ago IT administrators around the world were safe in the knowledge that their VPNs and WPA2 enterprise based wireless networks were safe, secure and based around a long standing authentication protocol named MS-CHAP2, dreamt up by Microsoft in the earliest days of NT 4.0 and fi nally implemented as a service in the service pack 4 update.