Input validation vulnerability in Multiple Post Passwords 1.1.1

The Multiple Post Passwords plugin for WordPress is vulnerable to a type of cyber attack known as Stored Cross-Site Scripting. This attack can be done by anyone with administrator-level permissions on WordPress websites that are running any version up to and including 1.1.1. When a user visits an affected page, malicious code is executed. This type of attack is only possible on multi-site WordPress installations or on installations where unfiltered_html has been disabled.