CVE-2025-28991 is a high-severity vulnerability classified under CWE-98, which pertains to improper control of filenames used in include or require statements within PHP applications. Specifically, this vulnerability affects the 'Evon' theme developed by snstheme, versions up to 3.4. The flaw allows an attacker to perform a Remote File Inclusion (RFI) attack, whereby malicious external files can be included and executed within the context of the vulnerable PHP application. This occurs due to insufficient validation or sanitization of user-supplied input that controls the filename parameter in include/require statements. 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). Although the attack complexity is rated high, no privileges or user interaction are needed, making exploitation feasible in certain scenarios where the attacker can supply crafted input. Successful exploitation can lead to full compromise of the affected web server, resulting in complete loss of confidentiality, integrity, and availability. Attackers can execute arbitrary PHP code, potentially leading to data theft, defacement, or pivoting to internal networks. No known public exploits or patches are currently available, increasing the urgency for affected organizations to assess and mitigate the risk proactively. The vulnerability was published on June 17, 2025, and reserved in March 2025, indicating recent discovery and disclosure. The affected product, Evon, is a PHP-based theme likely used in content management systems or e-commerce platforms, which may be deployed in various European organizations relying on snstheme products for their web presence.

For European organizations, the impact of CVE-2025-28991 can be significant, especially for those using the Evon theme in their web infrastructure. Exploitation could lead to unauthorized remote code execution, allowing attackers to access sensitive customer data, intellectual property, or internal systems. This can result in data breaches violating GDPR regulations, leading to legal penalties and reputational damage. The availability of affected systems may also be compromised, disrupting business operations and causing financial losses. Sectors such as e-commerce, government portals, and service providers that rely on PHP-based web applications with the Evon theme are particularly at risk. Additionally, the high confidentiality and integrity impact means attackers could manipulate website content, inject malware, or use compromised servers as a foothold for further attacks within European networks. Given the lack of patches and known exploits, organizations may face challenges in immediate remediation, increasing exposure time. The high attack complexity somewhat limits exploitation to skilled attackers who can craft suitable payloads, but the absence of authentication requirements broadens the threat surface.

1. Immediate code audit: Organizations should review all include/require statements in the Evon theme codebase to ensure that filenames are strictly validated against a whitelist of allowed files or sanitized to prevent injection of remote URLs or arbitrary paths. 2. Disable allow_url_include: Ensure the PHP configuration directive 'allow_url_include' is set to 'Off' to prevent inclusion of remote files via URL, reducing RFI risk. 3. Web application firewall (WAF): Deploy and configure WAF rules to detect and block suspicious requests attempting to exploit file inclusion vulnerabilities, such as those containing URL schemes or directory traversal patterns. 4. Network segmentation: Limit the web server's access to internal resources to minimize impact if compromise occurs. 5. Monitoring and logging: Enable detailed logging of web server and PHP errors to detect anomalous inclusion attempts and respond promptly. 6. Vendor engagement: Contact snstheme for updates or patches and subscribe to their security advisories. 7. Temporary mitigation: If patching is not immediately possible, consider disabling or replacing the Evon theme or restricting access to vulnerable endpoints via IP whitelisting or authentication mechanisms. 8. Security testing: Conduct penetration testing focused on file inclusion vectors to validate the effectiveness of mitigations.