OleumTech WIO DH2 Wireless Gateway and Sensor Wireless I/O Modules rely exclusively on a time value for entropy in key generation, which makes it easier for remote attackers to defeat cryptographic protection mechanisms by predicting the time of project creation.
https://www.cisa.gov/news-events/ics-advisories/icsa-14-202-01a
http://www.securityfocus.com/bid/68800