CVE-2025-39402 is a critical vulnerability classified under CWE-434, which pertains to the unrestricted upload of files with dangerous types. This vulnerability affects the mojoomla WPAMS product, specifically all versions up to and including 44.0 as of August 17, 2023. The core issue is that the WPAMS plugin does not properly restrict or validate the types of files that can be uploaded by authenticated users with low privileges (PR:L), allowing them to upload malicious files such as web shells. These web shells can then be executed on the web server, leading to full compromise of the affected system. The vulnerability has a CVSS 3.1 base score of 9.9, indicating critical severity, with an attack vector of network (AV:N), low attack complexity (AC:L), requiring privileges (PR:L) but no user interaction (UI:N). The scope is changed (S:C), meaning the vulnerability affects resources beyond the initially vulnerable component. The impact on confidentiality, integrity, and availability is high (C:H/I:H/A:H), reflecting the potential for complete system takeover, data theft, defacement, or denial of service. Although no known exploits are currently reported in the wild, the nature of the vulnerability and its ease of exploitation make it a significant threat. The lack of available patches at the time of publication further increases risk. The vulnerability arises from insufficient validation and filtering of uploaded files, allowing attackers to bypass restrictions and place executable code on the server. This type of vulnerability is particularly dangerous in web applications that handle user-generated content and is a common vector for initial compromise in targeted attacks.

For European organizations, the impact of CVE-2025-39402 can be severe. Organizations using mojoomla WPAMS for content management or other web services are at risk of having their web servers compromised through the upload of malicious web shells. This can lead to unauthorized access to sensitive data, including personal data protected under GDPR, intellectual property theft, disruption of services, and potential use of compromised servers as pivot points for further attacks within the network. The critical nature of the vulnerability means attackers can achieve full control over affected systems, potentially leading to ransomware deployment, data destruction, or espionage. Given the widespread use of WordPress and related plugins in Europe, especially among SMEs and public sector entities, the threat could impact a broad range of sectors including government, healthcare, finance, and education. The absence of patches at the time of disclosure means organizations must rely on immediate mitigations to reduce exposure. Additionally, the vulnerability could be exploited to undermine trust in affected organizations and cause reputational damage.

1. Immediate mitigation should include disabling file upload functionality in WPAMS if not essential, or restricting upload permissions to highly trusted users only. 2. Implement strict server-side validation and filtering of uploaded files, ensuring only safe file types are accepted and executable permissions are not granted to uploaded content directories. 3. Employ web application firewalls (WAFs) with rules designed to detect and block web shell upload attempts and suspicious file types. 4. Monitor web server logs and file system changes for indicators of compromise, such as unexpected file uploads or execution patterns. 5. Segregate and harden web server environments to limit the impact of a potential compromise, including running web services with least privilege and disabling unnecessary execution capabilities. 6. Regularly update and patch WPAMS and all related components as soon as vendor patches become available. 7. Conduct security awareness training for administrators and users about the risks of file uploads and suspicious activity. 8. Consider deploying endpoint detection and response (EDR) solutions to detect post-exploitation behaviors. 9. Review and tighten authentication and authorization controls to minimize the number of users who can upload files. 10. If possible, implement content security policies and disable execution of uploaded files in upload directories.