The UpdraftPlus WordPress Backup Plugin WordPress plugin before 1.22.9 does not sanitise and escape the updraft_interval parameter before outputting it back in an admin page, leading to a Reflected Cross-Site Scripting (XSS) vulnerability.
https://wpscan.com/vulnerability/7337543f-4c2c-4365-aebf-3423e9d2f872
http://packetstormsecurity.com/files/166631/WordPress-UpdraftPlus-Cross-Site-Scripting.html