The Meta Tag Manager WordPress plugin before 3.3 does not restrict which roles can create http-equiv refresh meta tags.
Missing Authorization vulnerability in Marcus (aka @msykes) Meta Tag Manager meta-tag-manager.This issue affects Meta Tag Manager: from n/a through <= 3.1.
The Meta Tag Manager plugin for WordPress is vulnerable to PHP Object Injection in all versions up to, and including, 3.0.2 via deserialization of untrusted input in the get_post_data function. This makes it possible for authenticated attackers, with contributor access or higher, to inject a PHP Object. No POP chain is present in the vulnerable plugin. If a POP chain is present via an additional plugin or theme installed on the target system, it could allow the attacker to delete arbitrary files, retrieve sensitive data, or execute code.