CVE-2025-53435 is a vulnerability classified as 'Improper Control of Filename for Include/Require Statement in PHP Program,' commonly known as a Remote File Inclusion (RFI) flaw, found in the axiomthemes Plan My Day WordPress theme. This vulnerability arises because the theme improperly validates or sanitizes user-supplied input used in PHP include or require statements, allowing an attacker to specify a remote file to be included and executed by the server. The affected versions include all releases up to and including 1.1.13. The vulnerability is remotely exploitable over the network without requiring authentication or user interaction, as indicated by the CVSS vector (AV:N/AC:H/PR:N/UI:N). The CVSS score of 8.1 reflects a high severity, with potential impacts on confidentiality, integrity, and availability. Successful exploitation can lead to arbitrary code execution, enabling attackers to execute malicious PHP code, steal sensitive data, modify website content, or disrupt service availability. Although no known exploits are currently reported in the wild, the vulnerability's characteristics make it a critical concern for websites using this theme. The lack of available patches at the time of publication increases the urgency for mitigation. The vulnerability was reserved on 2025-06-30 and published on 2025-12-18, indicating recent discovery and disclosure. The improper control of file inclusion is a common and dangerous web application security issue, often exploited to gain full control over vulnerable web servers.

For European organizations, the impact of CVE-2025-53435 can be severe, especially for those relying on the Plan My Day theme for their WordPress websites. Exploitation could lead to unauthorized remote code execution, resulting in data breaches involving personal or sensitive information, defacement of websites, or complete service outages. This can damage organizational reputation, lead to regulatory non-compliance under GDPR due to data exposure, and cause financial losses from downtime and remediation costs. Given the high adoption of WordPress across Europe, especially in sectors like e-commerce, media, and public services, the risk is amplified. Attackers could leverage this vulnerability to establish persistent backdoors, pivot within networks, or launch further attacks against internal systems. The lack of authentication and user interaction requirements lowers the barrier for exploitation, increasing the likelihood of automated scanning and attacks. The potential for widespread impact is significant if organizations do not promptly address the vulnerability.

1. Immediate monitoring for updates from axiomthemes and applying patches as soon as they are released is critical. 2. Until patches are available, restrict PHP include paths using server configuration (e.g., open_basedir in PHP) to prevent inclusion of remote files. 3. Employ Web Application Firewalls (WAFs) with rules specifically designed to detect and block suspicious file inclusion attempts targeting the Plan My Day theme. 4. Conduct thorough code reviews and sanitize all user inputs that influence file paths in custom theme modifications. 5. Disable allow_url_include in PHP configurations to prevent remote file inclusion. 6. Implement network-level controls to restrict outbound HTTP/HTTPS requests from web servers to prevent fetching malicious remote files. 7. Regularly scan websites for indicators of compromise and anomalous file changes. 8. Educate web administrators on the risks of RFI vulnerabilities and best practices for secure theme management. 9. Consider isolating WordPress instances in containerized or sandboxed environments to limit potential damage. 10. Maintain up-to-date backups to enable rapid recovery in case of compromise.