CVE-2025-13646 is a vulnerability classified under CWE-434 (Unrestricted Upload of File with Dangerous Type) found in the wpchill Image Gallery – Photo Grid & Video Gallery WordPress plugin, specifically in version 2.13.1. The flaw exists in the 'ajax_unzip_file' function, which fails to properly validate file types during upload. Authenticated users with Author-level permissions or higher can exploit this by uploading arbitrary files, bypassing normal restrictions. The vulnerability is exacerbated by a race condition that can be leveraged to increase the chances of successful exploitation. This can lead to remote code execution (RCE) on the web server hosting the WordPress site, allowing attackers to execute malicious code, compromise server integrity, steal data, or disrupt service availability. The attack vector is network-based, requiring authentication but no user interaction beyond the attacker's own actions. The vulnerability affects WordPress sites using the specified plugin version, which is popular for managing image galleries and video content. Although no exploits have been reported in the wild yet, the high CVSS score (7.5) indicates a significant risk if weaponized. The vulnerability highlights the importance of strict file validation and secure coding practices in web applications, especially those with user-generated content capabilities.

For European organizations, this vulnerability poses a significant threat to websites running WordPress with the affected plugin version. Successful exploitation can lead to full server compromise, data breaches, defacement, or service outages. Confidentiality is at risk due to potential data exfiltration; integrity is compromised by possible unauthorized code execution and content manipulation; availability may be disrupted by denial-of-service conditions or malicious payloads. Organizations relying on WordPress for public-facing websites, e-commerce, or internal portals could face reputational damage and regulatory consequences under GDPR if personal data is exposed. The requirement for Author-level access limits the attack surface but does not eliminate risk, especially in environments with multiple contributors or weak internal controls. The lack of known exploits in the wild provides a window for proactive mitigation before widespread attacks occur.

1. Immediately update the wpchill Image Gallery – Photo Grid & Video Gallery plugin to a patched version once available. If no patch exists, consider disabling or uninstalling the plugin temporarily. 2. Restrict Author-level permissions strictly, ensuring only trusted users have such access. 3. Implement web application firewalls (WAF) with rules to detect and block suspicious file upload patterns and race condition exploitation attempts. 4. Monitor server logs for unusual file uploads, especially ZIP or archive files, and unexpected file types in upload directories. 5. Harden the WordPress environment by disabling PHP execution in upload directories to prevent execution of malicious files. 6. Conduct regular security audits and vulnerability scans focusing on plugins and user privilege management. 7. Educate content authors about the risks of uploading untrusted files and enforce strict content policies. 8. Employ intrusion detection systems (IDS) to alert on anomalous activities related to file uploads and code execution attempts.