Vulnerabilities

The Custom Content Shortcode WordPress plugin through 4.0.2 does not validate one of its shortcode attribute, which could allow users with a contributor role and above to include arbitrary files via a traversal attack. This could also allow them to read non PHP files and retrieve their content. RCE could also be achieved if the attacker manage to upload a malicious image containing PHP code, and then include it via the affected attribute, on a default WP install, authors could easily achieve that given that they have the upload_file capability.

The Custom Content Shortcode WordPress plugin before 4.0.2 does not escape custom fields before outputting them, which could allow Contributor+ (v < 4.0.1) or Admin+ (v < 4.0.2) users to perform Cross-Site Scripting attacks even when the unfiltered_html is disallowed. Please note that such attack is still possible by admin+ in single site blogs by default (but won't be when the unfiltered_html is disallowed)