The Posti Shipping plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via the account_number and secret_key parameters in all versions up to, and including, 3.10.3 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.

The Posti Shipping plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 3.10.3. This is due to missing or incorrect nonce validation on the generate_notices_html() function. This makes it possible for unauthenticated attackers to inject malicious web scripts via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.