The EventON - WordPress Virtual Event Calendar Plugin plugin for WordPress is vulnerable to unauthorized modification of data and loss of data due to a missing capability check on the evo_eventpost_update_meta function in all versions up to, and including, 4.5.4 (for Pro) and 2.2.7 (for free). This makes it possible for unauthenticated attackers to update and remove arbitrary post metadata. Note that certain parameters may allow for content injection.