Breaking SSL Using Time Synchronisation Attacks presented at Defcon 2015

by Jose Selvi,

Summary : What time? When? Who is first? Obviously, Time is strongly present in our daily life. We use time in almost everything we do, and computers are not an exception to this rule. Our computers and devices use time in a wide variety of ways such as cache expiration, scheduling tasks or even security technologies. Some of those technologies completely relies on the local clock, and they can be affected by a clock misconfiguration.
However, since most operating system providers do not offer secure time synchronisation protocols by default, an attacker could manipulate those protocols and control the local clock. In this presentation, we review how different operating systems synchronise their local clocks and how an attacker could exploit some of them in order to bypass different well-known security protections.