Security advisory for The Mapster WP Maps plugin for WordPress

Advisory overview

The Mapster WP Maps plugin for WordPress is vulnerable to Stored Cross-Site Scripting in versions up to, and including, 2.0.5. This is due to the /wp-json/mapster-wp-maps/save-mapmaker REST route being registered with a permission_callback that unconditionally returns true (no capability check, no nonce), together with the mapster_write_config_to_acf() helper only sanitizing string config values with sanitize_text_field() — which strips HTML tags but leaves quote characters intact — and the mapster_wp_map shortcode renderer in mapster_wordpress_maps_shortcode_display() concatenating the stored loading_background_color value into a single-quoted inline style attribute without esc_attr(). This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Related references

• https://plugins.trac.wordpress.org/browser/mapster-wp-maps/tags/2.0.5/admin/api/class-mapster-wordpress-maps-api.php#L487
• https://plugins.trac.wordpress.org/browser/mapster-wp-maps/tags/2.0.5/admin/api/config-converter.php#L523
• https://plugins.trac.wordpress.org/browser/mapster-wp-maps/tags/2.0.5/admin/api/field-map.php#L304
• https://plugins.trac.wordpress.org/browser/mapster-wp-maps/tags/2.0.5/public/class-mapster-wordpress-maps-public.php#L262
• https://plugins.trac.wordpress.org/browser/mapster-wp-maps/tags/2.0.6/public/class-mapster-wordpress-maps-public.php
• https://www.wordfence.com/threat-intel/vulnerabilities/id/de1c951f-8b01-44cf-b192-412de9fae4fa?source=cve