Fix the open redirect vulnerability

Unfortunately www.remarpro.com don’t publish the detailed reason why they close a plugin.

One security vulnerability that this plugin has is an “open redirect” vulnerability – anyone can use a URL on your site to bounce visitors to their site, using the credibility of your site’s URL to get people to visit theirs.

This can be fixed by editing the file sermon.php in the plugin:

1. In the function sb_increase_download_count, change the line $wpdb->query("UPDATE ".$wpdb->prefix."sb_stuff SET COUNT=COUNT+1 WHERE name='".esc_sql($stuff_name)."'"); by adding return at the front, so that it goes return $wpdb->...
2. Find the two places in the same file where there is: header("Location: ".$url);. Each time on the previous line you will find sb_increase_download_count($file_name). Change that to if (sb_increase_download_count($file_name)) { and then add the closing brace, }, on the line after the header("Location: ".$url);
What this does is makes the plugin only issue a redirect to one of your saved sermons, not to any URL than an attacker sends in.

As I say, I can’t tell you whether there are other vulnerabilities.