CVE-2024-5440 is a medium-severity stored Cross-Site Scripting (XSS) vulnerability affecting the If-So Dynamic Content Personalization WordPress plugin versions prior to 1.8.0.3. 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 privileges or higher to inject malicious scripts that are stored persistently and executed in the context of other users viewing the affected content. The vulnerability is classified under CWE-79, indicating it is a classic XSS issue. The CVSS 3.1 base score is 5.4, reflecting a medium severity level, with the vector indicating network attack vector (AV:N), low attack complexity (AC:L), requiring privileges (PR:L), user interaction (UI:R), scope changed (S:C), and partial impact on confidentiality and integrity (C:L/I:L) but no impact on availability (A:N). No known exploits are currently reported in the wild, and no patches or updates have been linked yet. The vulnerability is particularly concerning because contributor-level users, who can submit content but not publish it directly, can exploit this to inject scripts that execute when other users, including administrators or editors, view the content. This could lead to session hijacking, privilege escalation, or other malicious activities depending on the payload. The plugin is used for dynamic content personalization on WordPress sites, which are widely deployed across many European organizations for marketing, e-commerce, and content management purposes.

For European organizations, this vulnerability poses a risk primarily to the confidentiality and integrity of web applications using the If-So Dynamic Content Personalization plugin. Attackers with contributor access could leverage this flaw to execute stored XSS attacks, potentially compromising user sessions, stealing sensitive data, or performing actions on behalf of privileged users. This could lead to unauthorized access to internal systems or data breaches, especially if administrators or editors are targeted. The impact is heightened in sectors with strict data protection regulations such as GDPR, where unauthorized data exposure could result in legal and financial penalties. Additionally, organizations relying on WordPress for customer-facing websites or intranets could suffer reputational damage if exploited. Although availability is not directly affected, the indirect consequences of trust erosion and potential regulatory fines are significant. The requirement for contributor-level privileges limits the attack surface somewhat but does not eliminate risk, as many organizations allow multiple users to contribute content. The lack of known exploits in the wild suggests limited immediate threat but does not preclude future exploitation.

European organizations should take the following specific actions to mitigate this vulnerability: 1) Immediately identify and inventory WordPress sites using the If-So Dynamic Content Personalization plugin and verify the installed version. 2) Upgrade the plugin to version 1.8.0.3 or later as soon as it becomes available, since this version addresses the vulnerability. 3) Until patching is possible, restrict contributor-level permissions to trusted users only and implement strict content review workflows to detect and block malicious shortcode usage. 4) Employ Web Application Firewalls (WAFs) with custom rules to detect and block suspicious shortcode attributes or script injection attempts. 5) Conduct regular security audits and scanning of WordPress sites to identify XSS vulnerabilities and malicious content. 6) Educate content contributors about the risks of injecting untrusted content and enforce input validation policies. 7) Monitor logs for unusual activity related to shortcode usage or contributor actions. 8) Consider disabling or replacing the plugin if it is not essential, especially in high-risk environments. These measures go beyond generic advice by focusing on access control, monitoring, and layered defenses tailored to the plugin’s usage context.