CVE-2024-13719 is an authorization bypass vulnerability classified under CWE-862 (Missing Authorization) affecting the PeproDev Ultimate Invoice plugin for WordPress, versions up to and including 2.0.8. The vulnerability arises from an insecure direct object reference (IDOR) in the invoicing viewer component, where a user-controlled key parameter is not properly validated for authorization. This flaw allows unauthenticated attackers to access invoice data related to completed orders without any authentication or user interaction. The invoices can contain sensitive personally identifiable information (PII) such as customer names, addresses, contact details, and potentially financial information. The vulnerability has a CVSS 3.1 base score of 5.3, reflecting its medium severity, with an attack vector of network (remote), low attack complexity, no privileges required, and no user interaction needed. Although no public exploits have been reported yet, the exposure of PII can lead to privacy violations, identity theft, and compliance issues. The root cause is the lack of proper authorization checks on the key parameter used to retrieve invoice data, which should have been validated against the requesting user's permissions. This vulnerability highlights the importance of implementing strict access controls and validating all user inputs in web applications, especially those handling sensitive data. Since the plugin is widely used in WordPress e-commerce environments, the vulnerability poses a risk to many organizations that rely on it for invoicing functionality.

The primary impact of CVE-2024-13719 is the unauthorized disclosure of personally identifiable information (PII) contained in invoices, which can include customer names, addresses, contact information, and potentially payment details. This exposure can lead to privacy breaches, identity theft, and reputational damage for affected organizations. Additionally, organizations may face regulatory compliance violations under data protection laws such as GDPR, CCPA, or others depending on jurisdiction. Although the vulnerability does not allow modification or deletion of data, the confidentiality breach alone can have serious consequences. The ease of exploitation—requiring no authentication or user interaction—means attackers can automate data harvesting at scale. This increases the risk of mass data leaks from multiple affected sites. E-commerce businesses and service providers using the PeproDev Ultimate Invoice plugin are particularly at risk, as their customer data is directly exposed. The vulnerability also undermines customer trust and could lead to financial losses due to fraud or legal penalties. Given the widespread use of WordPress and this plugin, the scope of affected systems is significant worldwide.

To mitigate CVE-2024-13719, organizations should immediately update the PeproDev Ultimate Invoice plugin to a patched version once released by the vendor. If a patch is not yet available, temporary mitigations include restricting access to the invoicing viewer endpoint via web application firewall (WAF) rules or IP whitelisting to trusted users only. Implementing strict access controls at the web server or application level to ensure only authenticated and authorized users can access invoice data is critical. Reviewing and hardening the plugin’s authorization logic by validating user permissions against requested invoice identifiers is essential. Monitoring web server logs for suspicious access patterns to the invoicing viewer can help detect exploitation attempts. Additionally, organizations should audit and minimize the amount of PII stored in invoices and ensure data encryption at rest and in transit. Regular security assessments and penetration testing of WordPress plugins handling sensitive data are recommended to identify similar issues proactively. Finally, educating site administrators about the risks of using outdated plugins and encouraging timely updates will reduce exposure to such vulnerabilities.