CVE-2024-8187 is a medium-severity Stored Cross-Site Scripting (XSS) vulnerability affecting the Smart Post Show WordPress plugin versions prior to 3.0.1, specifically version 3.0.0. The vulnerability arises because the plugin fails to properly sanitize and escape certain settings, allowing high-privilege users, such as administrators, to inject malicious scripts that are persistently stored and executed in the context of other users viewing the affected pages. Notably, this vulnerability can be exploited even when the unfiltered_html capability is disabled, such as in multisite WordPress setups, which typically restrict the ability to post raw HTML. The CVSS 3.1 base score of 4.8 reflects the medium severity, with an attack vector of network (remote), low attack complexity, requiring high privileges, and user interaction. The impact scope is changed (S:C), meaning the vulnerability can affect resources beyond the vulnerable component. The confidentiality and integrity impacts are low, while availability is not affected. No known exploits are currently reported in the wild, and no official patches or updates have been linked yet. This vulnerability is categorized under CWE-79, which is a common web application security weakness related to improper neutralization of input leading to XSS attacks.

For European organizations using WordPress sites with the Smart Post Show plugin version 3.0.0 or earlier, this vulnerability poses a risk primarily to site administrators and users with elevated privileges. An attacker with admin access could inject malicious JavaScript that executes in the browsers of other users, potentially leading to session hijacking, privilege escalation, or theft of sensitive information. In multisite environments common in larger organizations or hosting providers, the risk is heightened because the vulnerability bypasses the usual unfiltered_html restrictions. Although the direct impact on confidentiality and integrity is rated low, the persistent nature of stored XSS can facilitate targeted attacks, phishing, or lateral movement within an organization’s web infrastructure. European organizations with public-facing WordPress sites, especially those in sectors like finance, healthcare, or government, where trust and data integrity are critical, could face reputational damage and regulatory scrutiny under GDPR if user data is compromised. The lack of known exploits currently limits immediate risk, but the presence of the vulnerability in a widely used CMS plugin underscores the need for vigilance.

To mitigate this vulnerability, European organizations should immediately verify if their WordPress installations use the Smart Post Show plugin version 3.0.0 or earlier. If so, they should upgrade to version 3.0.1 or later once available, as this will include the necessary sanitization and escaping fixes. Until an official patch is released, administrators should restrict plugin access strictly to trusted users and consider disabling or removing the plugin if it is not essential. Implementing a Web Application Firewall (WAF) with rules to detect and block suspicious script injections in plugin settings can provide temporary protection. Additionally, organizations should audit user privileges to ensure that only necessary users have admin rights, reducing the risk of exploitation. Regular security scanning and monitoring for unusual activity on WordPress sites can help detect exploitation attempts early. Educating administrators about the risks of stored XSS and safe plugin management practices is also recommended.