CVE-2025-34085 is a critical vulnerability identified in the Simple File List WordPress plugin developed by Element Engage LLC. The vulnerability arises from an unrestricted file upload flaw (CWE-434) combined with improper access control (CWE-306). Specifically, the plugin's upload endpoint (ee-upload-engine.php) attempts to restrict uploads by validating file extensions. However, this validation is circumvented because the plugin does not properly re-validate files after they are renamed. An attacker can initially upload a malicious PHP payload disguised as a benign file type such as .png. Subsequently, the attacker exploits the plugin’s rename functionality (ee-file-engine.php) to change the file extension from .png to .php, effectively bypassing the upload restrictions. This results in the malicious payload becoming executable on the server, enabling unauthenticated remote attackers to achieve remote code execution (RCE). The vulnerability affects all versions of the plugin prior to 4.2.3. The CVSS v4.0 base score is 10.0, indicating a critical severity with network attack vector, no required privileges or user interaction, and high impact on confidentiality, integrity, and availability. Although no known exploits in the wild have been reported yet, the ease of exploitation and the severity of impact make this a significant threat to WordPress sites using this plugin. The vulnerability allows complete server compromise, potentially leading to data theft, site defacement, malware distribution, or pivoting to internal networks.

For European organizations, this vulnerability poses a severe risk, especially for those relying on WordPress sites with the Simple File List plugin for document management or file sharing. Successful exploitation can lead to full server compromise, resulting in unauthorized access to sensitive data, disruption of services, and potential defacement or malware hosting. This can damage organizational reputation, lead to regulatory non-compliance (e.g., GDPR violations due to data breaches), and cause financial losses. Since the exploit requires no authentication or user interaction, attackers can automate attacks at scale, increasing the likelihood of widespread impact. Organizations in sectors such as government, finance, healthcare, and critical infrastructure, which often use WordPress for public-facing sites, are particularly at risk. Additionally, compromised servers can be used as launchpads for further attacks within corporate networks or to target other entities, amplifying the threat landscape in Europe.

European organizations should immediately verify if they use the Simple File List WordPress plugin and identify the version in use. The primary mitigation is to upgrade the plugin to version 4.2.3 or later, where this vulnerability is patched. If immediate upgrade is not feasible, organizations should disable the plugin or restrict access to the upload and rename endpoints via web application firewalls (WAFs) or server-level access controls. Implement strict file upload policies, including server-side validation of file types after any file operations such as renaming. Employ intrusion detection systems to monitor for suspicious file uploads or renaming activities. Regularly audit web server directories for unexpected PHP files or other executable content. Additionally, applying the principle of least privilege to the web server process and isolating WordPress instances can limit the impact of a successful exploit. Organizations should also ensure that backups are current and tested to enable rapid recovery if compromise occurs.