You Snooze, You Lose: Measuring PLC Cycle Times under Attacks


Matthias Niedermaier, Hochschule Augsburg; Jan-Ole Malchow, Freie Universität Berlin; Florian Fischer, Hochschule Augsburg; Daniel Marzin, Freie Universität Berlin; Dominik Merli, Hochschule Augsburg; Volker Roth, Freie Universität Berlin; Alexander von Bodisco, Hochschule Augsburg


In this work, we show that the electrical side of a Programmable Logic Controller (PLC), that is, the controlled process, can be influenced by packet flooding. This differs from already known Denial of Service (DoS) attacks as the target is the actual process and not network connectivity. We conducted our experiments with 16 devices from six vendors, giving a good overview of the current market. Except for one device, all are susceptible to network flooding attacks. In three cases, an attack even lead to a DoS on the electrical side, completely disrupting any controlled process. In addition, we show that well-known scanning tools have measurable impacts on PLCs. These findings should be taken into consideration by administrators and researchers planning scanning activities.

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@inproceedings {220588,
author = {Matthias Niedermaier and Jan-Ole Malchow and Florian Fischer and Daniel Marzin and Dominik Merli and Volker Roth and Alexander von Bodisco},
title = {You Snooze, You Lose: Measuring {PLC} Cycle Times under Attacks},
booktitle = {12th USENIX Workshop on Offensive Technologies (WOOT 18)},
year = {2018},
address = {Baltimore, MD},
url = {},
publisher = {USENIX Association},
month = aug