The Easy Social Feed WordPress plugin before 6.4.0 does not validate and escape some of its shortcode attributes before outputting them back in the page, which could allow users with a role as low as contributor to perform Stored Cross-Site Scripting attacks which could be used against high privilege users such as admin.
https://wpscan.com/vulnerability/3acc6940-13ec-40fb-8471-6b2f0445c543