The plugin 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 admins.
[woocs_show_current_currency currency='1" onmouseover="alert(/XSS/)" b=' text='ClickMe!']
[woocs_rates precision='1" onmouseover="alert(/XSS/)" b=']