The Gallery Custom Links plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'display_name (profile.php) + comment (wp-comments-post.php)' parameter in all versions up to, and including, 2.3.3 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. The exploit requires two coordinated inputs from the same authenticated attacker: an HTML comment payload stored in a comment body (preserved verbatim by WordPress comment kses) and a matching simple_html_dom noise key placed in the attacker's display_name (which survives esc_attr() intact), with substitution occurring after both filters have run during the plugin's default-on output-buffering pass over the full rendered page.
Attack Parameters
Impact Assessment
CVSS Vector v3.1