CVE-2024-6718 is a medium-severity vulnerability classified as CWE-79 (Cross-Site Scripting, XSS) affecting the WordPress plugin PVN Auth Popup up to version 1.0.0. The vulnerability arises because the plugin fails to properly validate and escape certain shortcode attributes before rendering them on pages or posts where the shortcode is embedded. This improper handling allows users with contributor-level permissions or higher to inject malicious scripts that are stored persistently within the content. When other users or administrators view the affected page or post, the malicious script executes in their browsers, potentially leading to session hijacking, privilege escalation, or unauthorized actions within the WordPress environment. The CVSS 3.1 base score is 5.4, indicating a medium severity level. The attack vector is network-based (remote), requires low attack complexity, and privileges at the contributor level, with user interaction needed (viewing the infected page). The scope is changed, meaning the vulnerability can affect components beyond the initially vulnerable plugin. No known exploits are currently reported in the wild, and no patches have been linked yet. This vulnerability is significant because contributor roles are common in WordPress sites, and stored XSS can have serious consequences, including site defacement, data theft, or further exploitation of the WordPress installation or its users.

For European organizations using WordPress sites with the PVN Auth Popup plugin, this vulnerability poses a risk of persistent XSS attacks that can compromise the confidentiality and integrity of site data and user sessions. Attackers with contributor access can embed malicious scripts that execute in the browsers of administrators or other users, potentially leading to credential theft, unauthorized content changes, or further malware deployment. This could result in reputational damage, data breaches involving personal or sensitive information, and disruption of web services. Given the widespread use of WordPress in Europe for corporate, governmental, and non-profit websites, exploitation could affect a broad range of sectors. The medium CVSS score reflects moderate impact, but the changed scope and stored nature of the XSS increase the risk of cascading effects. Additionally, compliance with GDPR and other data protection regulations in Europe means that exploitation leading to data leakage could have legal and financial consequences.

European organizations should immediately audit their WordPress installations to identify the presence of the PVN Auth Popup plugin, especially versions up to 1.0.0. Until an official patch is released, administrators should consider disabling or removing the plugin to eliminate the attack surface. Restrict contributor role assignments to trusted users only and review existing contributor content for suspicious shortcode usage. Implement Web Application Firewall (WAF) rules that detect and block common XSS payloads in shortcode attributes. Employ Content Security Policy (CSP) headers to limit script execution sources and reduce the impact of injected scripts. Regularly update WordPress core and plugins to the latest versions once patches become available. Additionally, monitor logs for unusual activity related to shortcode usage and user content submissions. Educate content contributors about the risks of embedding untrusted code or scripts. Finally, conduct security testing focused on shortcode handling to proactively identify similar vulnerabilities.