OpenNMS version 18.0.1 and prior are vulnerable to a stored XSS issue due to insufficient filtering of SNMP trap supplied data. By creating a malicious SNMP trap, an attacker can store an XSS payload which will trigger when a user of the web UI views the events list page. This issue was fixed in version 18.0.2, released on September 20, 2016.
Credits
This issue was discovered by Matthew Kienow and disclosure was coordinated by Rapid7.
