Cross-site Scripting in OpenNMS Horizon

In OpenNMS Horizon, versions opennms-1-0-stable through opennms-27.1.1; OpenNMS Meridian, versions meridian-foundation-2015.1.0-1 through meridian-foundation-2019.1.18-1; meridian-foundation-2020.1.0-1 through meridian-foundation-2020.1.6-1 are vulnerable to Stored Cross-Site Scripting, since the function validateFormInput() performs improper validation checks on the input sent to the groupName and groupComment parameters. Due to this flaw, an authenticated attacker could inject arbitrary script and trick other admin users into downloading malicious files which can cause severe damage to the organization using opennms.