CVE-2025-8418 is a high-severity vulnerability affecting the B Slider - Gutenberg Slider Block for WordPress plugin, developed by bplugins. This vulnerability arises from a missing authorization check (CWE-862) in the plugin's activated_plugin function, which fails to properly verify user capabilities before allowing plugin installation. As a result, any authenticated user with subscriber-level access or higher can exploit this flaw to install arbitrary plugins on the WordPress server. Since WordPress plugins can execute PHP code, this arbitrary plugin installation can lead to remote code execution (RCE), enabling attackers to fully compromise the affected server. The vulnerability affects all versions up to and including 1.1.30 of the plugin. The CVSS v3.1 base score is 8.8, reflecting the network attack vector, low attack complexity, requirement for low privileges (authenticated subscriber), no user interaction, and high impact on confidentiality, integrity, and availability. No patches or fixes have been published yet, and there are no known exploits in the wild at the time of disclosure. However, the ease of exploitation combined with the potential for full server compromise makes this a critical risk for WordPress sites using this plugin.

For European organizations, this vulnerability poses a significant threat, especially for those relying on WordPress sites with the B Slider plugin installed. Exploitation can lead to full server compromise, data breaches involving sensitive customer or business data, defacement of websites, and potential use of compromised servers for further attacks such as phishing or malware distribution. Given the widespread use of WordPress across European businesses, including SMEs and large enterprises, the impact could be broad. Organizations in regulated sectors (e.g., finance, healthcare) face additional risks due to potential violations of GDPR and other data protection laws, which mandate strict controls over personal data security. The ability for low-privilege users to escalate privileges and execute arbitrary code also threatens the integrity and availability of web services, potentially causing reputational damage and operational disruption.

Immediate mitigation steps include: 1) Temporarily restricting subscriber-level users from accessing plugin management areas until a patch is available. 2) Monitoring WordPress user roles and permissions to ensure no unnecessary elevation of privileges is granted. 3) Implementing web application firewalls (WAFs) with rules to detect and block suspicious plugin installation attempts. 4) Regularly auditing installed plugins and removing unused or untrusted plugins. 5) Applying principle of least privilege to WordPress user roles, limiting subscriber accounts strictly to content consumption. 6) Keeping WordPress core and all plugins updated and subscribing to vulnerability advisories for timely patch application once available. 7) Employing intrusion detection systems to monitor for unusual file changes or plugin installations. 8) Considering temporary disabling of the vulnerable plugin if business operations allow. These steps go beyond generic advice by focusing on user role management, monitoring, and proactive controls specific to WordPress plugin management.