Unitronics VisiLogic OPLC IDE before 9.8.02 does not properly restrict access to ActiveX controls, which allows remote attackers to have an unspecified impact via a crafted web site.
https://ics-cert.us-cert.gov/advisories/ICSA-15-274-02
http://www.zerodayinitiative.com/advisories/ZDI-15-580
http://www.zerodayinitiative.com/advisories/ZDI-15-579
http://www.zerodayinitiative.com/advisories/ZDI-15-578
http://www.zerodayinitiative.com/advisories/ZDI-15-577