The PeproDev Ultimate Invoice plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 2.0.8 via the invoicing viewer due to missing validation on a user controlled key. This makes it possible for unauthenticated attackers to view invoices for completed orders which can contain PII of users.

Improper Neutralization of Input During Web Page Generation (XSS or 'Cross-site Scripting') vulnerability in Pepro Dev. Group PeproDev Ultimate Invoice allows Stored XSS.This issue affects PeproDev Ultimate Invoice: from n/a through 2.0.6.

Missing Authorization vulnerability in Pepro Dev. Group PeproDev Ultimate Invoice.This issue affects PeproDev Ultimate Invoice: from n/a through 2.0.0.

Exposure of Sensitive Information to an Unauthorized Actor vulnerability in Pepro Dev. Group PeproDev Ultimate Invoice.This issue affects PeproDev Ultimate Invoice: from n/a through 1.9.7.