CVE-2025-63017 is a Remote File Inclusion (RFI) vulnerability found in the fuelthemes WerkStatt WordPress plugin, specifically affecting versions up to and including 1.6.6. The root cause is improper control over the filename parameter used in PHP include or require statements, which allows an attacker to manipulate the input to include arbitrary files from remote locations. This vulnerability enables remote code execution without requiring user interaction, though it requires low-level privileges on the target system. The attacker can exploit this flaw by sending specially crafted HTTP requests that cause the plugin to include malicious PHP code hosted on an external server. Successful exploitation compromises the confidentiality, integrity, and availability of the affected web server and potentially the underlying network. The CVSS 3.1 score of 7.5 indicates a high severity, with network attack vector, high impact on all security properties, and requiring low privileges but no user interaction. No public exploits are currently known, but the vulnerability is publicly disclosed and should be treated as a critical risk. The vulnerability affects WordPress sites using the WerkStatt plugin, which is popular among European small and medium businesses for website design and e-commerce. The lack of available patches at the time of disclosure necessitates immediate mitigation steps to prevent exploitation.

For European organizations, exploitation of CVE-2025-63017 can lead to full compromise of web servers running the vulnerable WerkStatt plugin. This includes unauthorized disclosure of sensitive data, defacement or manipulation of website content, and potential pivoting to internal networks. Given the plugin’s use in business and e-commerce websites, attacks could disrupt operations, damage brand reputation, and lead to regulatory non-compliance under GDPR due to data breaches. The vulnerability’s remote exploitation capability means attackers can operate from anywhere, increasing the threat landscape. Organizations with public-facing WordPress sites are particularly vulnerable, especially if they have not applied updates or mitigations. The high impact on confidentiality, integrity, and availability makes this a critical concern for sectors handling personal data, financial transactions, or critical services. Additionally, the vulnerability could be leveraged in supply chain attacks or to distribute malware to site visitors, amplifying its impact across the European digital ecosystem.

1. Immediately update the WerkStatt plugin to a patched version once available from fuelthemes. Monitor vendor announcements for official patches. 2. Until patches are released, implement web application firewall (WAF) rules to block requests containing suspicious file inclusion patterns or remote URLs in parameters related to the plugin. 3. Restrict PHP include/require statements in the plugin code by applying input validation and sanitization to ensure only local, expected files can be included. 4. Disable allow_url_include and allow_url_fopen directives in PHP configuration to prevent remote file inclusion. 5. Conduct thorough code audits on custom plugins or themes to detect similar unsafe file inclusion practices. 6. Monitor web server logs for anomalous requests attempting to exploit file inclusion, such as those containing URL schemes or unexpected file paths. 7. Employ network segmentation to limit the impact of a compromised web server. 8. Educate administrators on the risks of outdated plugins and enforce timely patch management policies. 9. Use intrusion detection/prevention systems (IDS/IPS) tuned to detect RFI attack signatures targeting WordPress environments.