The changelog entry for the latest version of All-in-One Event Calendar by Time.ly is “Fixed XSS Security vulnerability by sanitizing the event input.” Looking at the changes made in that version that description is accurate and previously the plugin contained an authenticated persistent cross-site scripting (XSS) vulnerability. That is due to the fact that the plugin allows users with the Author role, which don’t have the unfiltered_html capability, to create new events and they could have saved malicious JavaScript to settings for an event, which would then be included on the event’s page.

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