CVE-2025-12563 is a vulnerability identified in the Blog2Social: Social Media Auto Post & Scheduler plugin for WordPress, affecting all versions up to and including 8.6.0. The root cause is a missing or incorrect authorization check (CWE-862) in the uploadVideo() function, which allows authenticated users with minimal privileges (Subscriber-level or higher) to upload MP4 files to the WordPress uploads directory (wp-content/uploads/<YYYY>/<MM>/). This capability check failure means that users who should not have upload permissions can bypass restrictions and place files on the server. Although the vulnerability only permits uploading MP4 files, which are typically media files, the risk lies in the potential for attackers to upload crafted files that could be used in chained attacks, such as embedding malicious content or exploiting other server-side weaknesses. The vulnerability does not require user interaction beyond authentication, and the attack vector is network accessible. The CVSS v3.1 base score is 4.3 (medium), reflecting low impact on confidentiality and availability but some integrity impact due to unauthorized file uploads. No public exploits have been reported yet, and no patches are currently linked, indicating the need for vendor action or user mitigation. The vulnerability affects a widely used WordPress plugin popular among social media marketers for automating posts, increasing the attack surface for websites using this plugin.

For European organizations, this vulnerability poses a moderate risk primarily to websites using the Blog2Social plugin for social media automation. Unauthorized file uploads by low-privilege users can lead to integrity issues, such as unauthorized content injection or defacement. While direct remote code execution is not indicated, attackers could leverage this to store malicious media or attempt further exploitation if other vulnerabilities exist in the hosting environment. This can damage brand reputation, disrupt marketing operations, and potentially expose organizations to compliance risks under GDPR if personal data is compromised through chained attacks. Organizations relying heavily on WordPress for their digital presence, especially in sectors like media, marketing, and e-commerce, may face increased risk. The vulnerability could also be exploited for hosting malicious content that might be used in phishing or malware distribution campaigns targeting European users.

European organizations should implement the following specific mitigations: 1) Immediately restrict plugin access to trusted users only and review user roles to minimize Subscriber-level accounts. 2) Monitor the wp-content/uploads directory for unauthorized or suspicious MP4 files and implement file integrity monitoring. 3) Apply strict server-side validation and filtering of uploaded files, ensuring only expected file types and sizes are accepted. 4) Disable or remove the Blog2Social plugin if not essential, or replace it with alternatives that have proper authorization controls. 5) Employ Web Application Firewalls (WAF) with custom rules to detect and block unauthorized upload attempts. 6) Keep WordPress core and all plugins updated and monitor vendor advisories for patches addressing this vulnerability. 7) Conduct regular security audits focusing on user permissions and plugin configurations. 8) Educate site administrators about the risks of granting upload capabilities to low-privilege users.