Clocking into The Network — Attacking KronosTimeclock Devices

Adversary Academy Research
3 min readSep 27, 2023


One of the services I’m most excited about at Adversary Academy is our targeted vulnerability research (TVR) program. The challenge I’ve seen with historical pentest providers is that there is typically a one to two-week engagement window and after that, you usually don’t hear from your pentest provider until it's time for next year's test. In order to disrupt that cycle We’ve started a program that allows for researchers to spend time attacking interesting systems they’ve encountered on customer networks, long after the engagement is over. Typically on a penetration test your “spidey senses” will go off at some point when you encounter a system that just feels vulnerable, or impactful if it were to be vulnerable. With the TVR program, we are able to spend cycles researching those items that appear to be high-impact.

One recent example was for a customer who employed the Kronos InTouch DX timeclock device. A really fancy Android based timeclock that supports biometric data as well as facial recognition.

For this engagement, the ability to jump to an enterprise network would be very valuable. We hypothesized that the Kronos Timeclock devices may be connected to an enterprise network and not properly segmented. Attempting to access all of the settings on the customer devices were locked out and non-default passwords were used. Later we purchased our own version of the hardware to perform a full teardown.

Further documentation available on the FCC report website shows that ssh is an option that can be configured on the device and that a maintenance mode badge or button can be used to bypass the initial configuration.

Pressing and holding the maintenance mode button (4) will bypass the locked screens

After bypassing the lockout and enabling SSH with a known password the user is logged in as root rather than a low privilege account. With root access, any configuration can be changed however one of the most valuable configuration files we found was the wpa_supplicant.conf file which contains the wifi credentials in plaintext. This file would allow a local attacker to then join the network that the Kronos time clock is connected to, potentially joining an enterprise network and carrying out further attacks once on the network.

our root access as rauser printing out the wpa_supplicant.conf file

After discovering this issue the Adversary Academy team reached out to Kronos and recommended that the wpa_supplicant file be wiped when maintenance mode is entered by physical keypress, which would better protect the wpa_supplicant.conf file, or alternatively making the Rauser non-root and only giving them access to the needed configuration files is also a suitable alternative. Currently no patch or update is available for this issue and we have yet to hear a response from Kronos / UGK.