CVE-2025-5733 is a vulnerability identified in the Modern Events Calendar Lite plugin for WordPress, affecting all versions up to and including 7.21.9. The vulnerability is classified under CWE-201, which involves the insertion of sensitive information into sent data. Specifically, this flaw allows unauthenticated attackers to perform Full Path Disclosure (FPD) due to improper or insufficient validation of the 'id' property when exporting calendar data. Full Path Disclosure means that an attacker can retrieve the absolute file system path of the web application on the server. While the disclosed information itself does not directly compromise the confidentiality, integrity, or availability of the system, it can be leveraged as reconnaissance data to facilitate further attacks, such as local file inclusion (LFI), remote code execution (RCE), or privilege escalation, especially if combined with other vulnerabilities. The vulnerability requires no authentication or user interaction, making it accessible to any remote attacker. The CVSS v3.1 score is 5.3 (medium severity), reflecting the limited direct impact but ease of exploitation and potential to aid in more severe attacks. No known exploits are currently reported in the wild, and no official patches or fixes are linked yet. The vulnerability affects a widely used WordPress plugin, which is popular for event management and calendar functionalities on websites.

For European organizations, the impact of CVE-2025-5733 is primarily in the realm of information disclosure that can facilitate more damaging attacks. Organizations using the Modern Events Calendar Lite plugin on their WordPress sites may inadvertently expose their server's directory structure, which can help attackers craft targeted exploits or identify other vulnerabilities. This can lead to increased risk of website defacement, data breaches, or service disruption if chained with other vulnerabilities. Given the widespread use of WordPress across Europe, including by SMEs, public institutions, and event organizers, this vulnerability could be a stepping stone for attackers targeting sensitive or high-profile websites. However, since the vulnerability alone does not allow direct compromise, the immediate risk is moderate. Still, organizations with sensitive data or critical web infrastructure should treat this as a significant reconnaissance risk that could precede more severe attacks.

1. Immediate mitigation involves updating the Modern Events Calendar Lite plugin to the latest version once the vendor releases a patch addressing this vulnerability. Until then, consider disabling the calendar export functionality or restricting access to it via web application firewalls (WAFs) or server-level access controls. 2. Implement strict input validation and sanitization on the 'id' parameter at the application or web server level to prevent malformed or malicious requests from triggering the vulnerability. 3. Use security plugins or WAFs that can detect and block suspicious requests targeting known vulnerable endpoints of the plugin. 4. Conduct regular security audits and vulnerability scans on WordPress installations to identify and remediate similar information disclosure issues. 5. Limit the exposure of sensitive server information in error messages and responses by configuring WordPress and the web server to suppress detailed error reporting. 6. Monitor web server logs for unusual access patterns to the calendar export functionality that could indicate exploitation attempts. 7. Educate site administrators about the risks of using outdated plugins and the importance of timely updates and patch management.