Blogs by Michiel

Tech blog on web, security & embedded

The NTP protocol is used by many devices to synchronize their system clocks. However, many devices use SNTP clients (Simple NTP) which are even more vulnerable to interference. As most (S)NTP packets are unauthenticated, they are vulnerable to spoofing, making it possible to change a device's time by manipulating (S)NTP packets.

In this blog, we discuss how (S)NTP packets can be forged to manipulate a device's system clock. Especially on the default SNTP client for many Linux systems, this turned out to be very easy. We will also dicuss the consequences of such attacks, as well as how these attacks can be prevented.