CVE-2025-62524 is a medium-severity information disclosure vulnerability affecting PILOS, a frontend platform for BigBlueButton used for interactive live online seminars. Versions of PILOS prior to 4.8.0 expose the PHP version through the X-Powered-By HTTP header, which is enabled by default in the underlying PHP base image. Additionally, the PHP version can be inferred from the PILOS version displayed in the footer of the web interface and by analyzing publicly available source code on GitHub. This exposure allows an unauthenticated remote attacker to fingerprint the server environment without any user interaction, providing valuable intelligence about the software stack. Such information can be leveraged to identify known exploits or vulnerabilities specific to the disclosed PHP version, facilitating targeted attacks. The vulnerability is categorized under CWE-200 (Exposure of Sensitive Information) and CWE-497 (Exposure of System Information). The issue does not directly compromise confidentiality, integrity, or availability but increases the attack surface by revealing system details. The vulnerability was addressed in PILOS version 4.8.0 by removing or obfuscating the PHP version information from HTTP headers and the user interface. No known exploits have been reported in the wild as of the publication date, but the disclosure still poses a risk to organizations relying on PILOS for secure communications.

For European organizations, especially those in education, healthcare, and government sectors using PILOS for live online seminars, this vulnerability can facilitate reconnaissance by malicious actors. By knowing the exact PHP version, attackers can tailor their exploits to known vulnerabilities in that PHP release, increasing the likelihood of successful attacks such as remote code execution or privilege escalation on the underlying server. Although the vulnerability itself does not allow direct compromise, it lowers the barrier for attackers to identify weaknesses in the infrastructure. This can lead to subsequent attacks that may result in data breaches, service disruptions, or unauthorized access to sensitive communications. Given the widespread adoption of BigBlueButton and its frontends like PILOS in European institutions for remote collaboration, the exposure could have a broad impact if not mitigated promptly. The medium severity rating reflects the indirect but meaningful risk posed by this information disclosure.

European organizations should immediately upgrade PILOS installations to version 4.8.0 or later, where the PHP version exposure has been patched. If upgrading is not immediately feasible, administrators should disable the X-Powered-By header in the PHP configuration (e.g., by setting 'expose_php = Off' in php.ini) to prevent PHP version disclosure. Additionally, customize or remove version information displayed in the PILOS footer to avoid indirect version fingerprinting. Regularly audit web server headers and application footers for unintended information disclosure. Employ web application firewalls (WAFs) to monitor and block suspicious reconnaissance activities. Maintain up-to-date threat intelligence to detect exploitation attempts targeting known PHP vulnerabilities. Finally, ensure that the underlying PHP environment and all related components are kept current with security patches to minimize the risk of exploitation based on the disclosed version information.