CVE-2025-53204 is a high-severity vulnerability classified under CWE-98, which pertains to improper control of filenames used in include or require statements within PHP programs. Specifically, this vulnerability affects the 'eventlist' product developed by ovatheme, up to version 1.9.2. The flaw allows for PHP Local File Inclusion (LFI), where an attacker can manipulate the filename parameter used in include or require statements to load arbitrary files from the local filesystem. This can lead to the execution of malicious code, disclosure of sensitive information, or complete compromise of the affected web application. The vulnerability is exploitable remotely over the network without requiring authentication or user interaction, although it has a high attack complexity, indicating some conditions must be met for successful exploitation. The CVSS v3.1 base score is 8.1, reflecting high impact on confidentiality, integrity, and availability. The vulnerability does not have known public exploits in the wild yet, but the potential for exploitation remains significant due to the nature of LFI vulnerabilities in PHP applications. The lack of available patches at the time of publication increases the urgency for mitigation and monitoring.

For European organizations using the ovatheme eventlist plugin, this vulnerability poses a significant risk. Exploitation could lead to unauthorized disclosure of sensitive data, including configuration files, credentials, or personal data protected under GDPR. Attackers could also execute arbitrary code, potentially leading to full system compromise, data tampering, or service disruption. This could result in operational downtime, reputational damage, regulatory penalties, and financial losses. Organizations in sectors with high reliance on web applications for event management, such as education, public administration, and cultural institutions, may be particularly vulnerable. The remote exploitability without authentication increases the risk of widespread attacks, especially if the plugin is used in publicly accessible web environments.

Immediate mitigation steps include: 1) Conduct an inventory to identify all instances of the ovatheme eventlist plugin in use. 2) Restrict web server permissions to limit file access, preventing unauthorized file inclusion. 3) Implement web application firewall (WAF) rules to detect and block suspicious requests attempting to exploit file inclusion vectors. 4) Apply input validation and sanitization on parameters controlling file inclusion to ensure only intended files can be loaded. 5) Monitor logs for unusual access patterns or errors indicative of attempted exploitation. 6) Engage with the vendor or community to obtain patches or updates addressing this vulnerability as soon as they become available. 7) Consider temporary disabling or removing the plugin if immediate patching is not feasible, especially in high-risk environments. 8) Educate developers and administrators about secure coding practices related to file inclusion to prevent similar issues in the future.