CVE-2024-6159 is a critical SQL Injection vulnerability identified in the WordPress plugin 'Push Notification for Post and BuddyPress' versions prior to 1.9.4. The vulnerability arises because the plugin fails to properly sanitize and escape user-supplied input parameters before incorporating them into SQL queries. Specifically, this flaw is exploitable via an AJAX action that is accessible to unauthenticated users, meaning that an attacker does not need to be logged in or have any privileges on the WordPress site to exploit it. The vulnerability is classified under CWE-89, which corresponds to SQL Injection, a well-known and dangerous class of injection flaws. Exploiting this vulnerability allows an attacker to manipulate the backend database queries, potentially leading to unauthorized data disclosure, data modification, or deletion, and in some cases, full system compromise. The CVSS v3.1 base score of 9.8 reflects the high severity, with attack vector being network-based (remote), no privileges required, no user interaction needed, and impacts on confidentiality, integrity, and availability all rated as high. Although no known exploits are currently reported in the wild, the ease of exploitation and critical impact make this vulnerability a significant threat to any WordPress site using the affected plugin version. The lack of an official patch link suggests that users should urgently check for updates or apply mitigations as recommended by the plugin vendor or security community.

For European organizations, the impact of this vulnerability can be substantial, especially for those relying on WordPress sites with the 'Push Notification for Post and BuddyPress' plugin installed. Successful exploitation could lead to unauthorized access to sensitive customer or business data stored in the WordPress database, including user credentials, personal information, or proprietary content. This could result in data breaches violating GDPR and other data protection regulations, leading to legal penalties and reputational damage. Additionally, attackers could modify or delete content, disrupt notification services, or use the compromised site as a foothold to launch further attacks within the organization's network. Given the plugin’s role in push notifications, disruption could also affect communication channels critical for customer engagement or internal alerts. The vulnerability’s remote and unauthenticated nature increases the risk profile, as attackers can exploit it without prior access. This is particularly concerning for European organizations with high web presence or those in sectors such as finance, healthcare, or government, where data sensitivity and regulatory compliance are paramount.

1. Immediate action should be to update the 'Push Notification for Post and BuddyPress' plugin to version 1.9.4 or later once available, as this version addresses the vulnerability. 2. If an update is not immediately available, temporarily disable the plugin to prevent exploitation. 3. Employ Web Application Firewalls (WAFs) with rules specifically designed to detect and block SQL injection attempts targeting WordPress AJAX endpoints. 4. Conduct a thorough audit of WordPress installations to identify all instances of the vulnerable plugin and verify their versions. 5. Monitor web server and application logs for suspicious AJAX requests that may indicate exploitation attempts. 6. Implement strict input validation and sanitization for all user inputs at the application level, even beyond plugin updates. 7. Restrict access to AJAX endpoints where feasible, for example by limiting requests to authenticated users or trusted IP ranges until patches are applied. 8. Regularly back up WordPress databases and files to enable rapid recovery in case of compromise. 9. Educate site administrators on the risks of installing plugins from unknown or unverified sources and encourage use of plugins with active maintenance and security support.