CVE-2025-63036 is a vulnerability classified as improper control of filename for include/require statements in PHP, specifically affecting the Ronneby Theme Core developed by DFDevelopment, versions up to and including 1.5.68. The flaw allows an attacker to exploit PHP Local File Inclusion (LFI), where the application fails to properly validate or sanitize user-supplied input used in include or require statements. This can lead to the inclusion of unintended files from the local filesystem, enabling attackers to execute arbitrary PHP code if they can control the content of included files or leverage other vulnerabilities such as log poisoning. The vulnerability is remotely exploitable over the network without requiring authentication or user interaction, increasing its risk profile. The CVSS 3.1 base score of 7.5 reflects a high severity due to the network attack vector, low attack complexity, no privileges required, no user interaction, and a significant impact on integrity (code execution), though confidentiality and availability impacts are not directly affected. While no public exploits are currently known, the vulnerability's nature makes it a prime target for attackers aiming to compromise websites running the affected theme. The Ronneby theme is popular among WordPress users for building visually rich websites, meaning a broad range of organizations could be affected if they have not updated their theme. The vulnerability stems from insecure coding practices where user input is directly used in file inclusion functions without adequate validation or sanitization, violating secure coding standards and increasing the attack surface.

For European organizations, this vulnerability poses a significant risk, especially for those relying on WordPress websites using the Ronneby theme for business operations, e-commerce, or media publishing. Successful exploitation can lead to arbitrary code execution on web servers, allowing attackers to manipulate website content, steal sensitive data, deploy malware, or pivot to internal networks. This can result in reputational damage, regulatory non-compliance (e.g., GDPR breaches if personal data is exposed), financial losses, and operational disruptions. Given the widespread use of WordPress across Europe and the popularity of premium themes like Ronneby, the scope of affected systems could be substantial. Attackers could leverage this vulnerability to establish persistent backdoors or deface websites, impacting customer trust and business continuity. The lack of required authentication and user interaction lowers the barrier for exploitation, increasing the likelihood of attacks. Additionally, organizations in sectors with high web presence such as retail, media, and professional services are at heightened risk. The vulnerability could also be exploited as part of larger attack chains targeting European infrastructure or supply chains that depend on vulnerable web assets.

Organizations should immediately verify if their WordPress installations use the Ronneby theme Core version 1.5.68 or earlier and plan to upgrade to a patched version once released by DFDevelopment. Until a patch is available, administrators should implement strict input validation and sanitization on any user-supplied data that could influence file inclusion paths. Employing Web Application Firewalls (WAFs) with custom rules to detect and block suspicious requests attempting to exploit LFI vectors can provide temporary protection. Restricting PHP functions such as include, require, and their variants through PHP configuration (e.g., disable_functions directive) or using open_basedir restrictions can limit file system access. Regularly auditing web server logs for unusual file inclusion attempts or errors can help detect exploitation attempts early. Additionally, isolating web servers in segmented network zones and enforcing the principle of least privilege on web application file permissions reduces the potential impact of a successful attack. Organizations should also ensure that backup and recovery procedures are in place to restore compromised systems quickly. Finally, educating developers and administrators on secure coding practices and theme/plugin management is essential to prevent similar vulnerabilities.