By intentionally failing to log in with a specially crafted and invalid username, a remote attacker with access to the OpenNMS web UI can cause a logged-in user's browser to execute arbitrary Javascript code when viewing the events and/or alarms browser in the OpenNMS web UI. An attacker does not need a valid login account, but does need to be able to reach the login page, in order to exploit this vulnerability.
By intentionally failing to log in with a specially crafted and invalid username, a remote attacker with access to the OpenNMS web UI can cause a logged-in user's browser to execute arbitrary Javascript code when viewing the events and/or alarms browser in the OpenNMS web UI. An attacker does not need a valid login account, but does need to be able to reach the login page, in order to exploit this vulnerability.