CVE-2025-34081 is a vulnerability classified under CWE-215, which involves the insertion of sensitive information into debugging code. Specifically, the Contec Co.,Ltd. CONPROSYS HMI System (CHS) versions prior to 3.7.7 expose a PHP phpinfo() debug page that is accessible without authentication. The phpinfo() page reveals detailed information about the PHP environment, server configuration, loaded modules, environment variables, and other sensitive data that can aid attackers in crafting targeted attacks or identifying further vulnerabilities. Since the page is exposed to unauthenticated users, any remote attacker can access this information without needing credentials or user interaction. The vulnerability has a CVSS 4.0 base score of 6.9, indicating a medium severity level, with an attack vector of network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), and no user interaction (UI:N). The impact is limited to confidentiality as the vulnerability leaks information but does not directly affect integrity or availability. No known exploits are currently reported in the wild, but the presence of such debug information can significantly aid attackers in reconnaissance and subsequent exploitation steps. The vulnerability affects all versions before 3.7.7 of the CONPROSYS HMI System, a human-machine interface product used in industrial automation and control systems. The lack of patch links suggests that a fix may be forthcoming or that users should contact the vendor for updates.

For European organizations, especially those in industrial automation, manufacturing, and critical infrastructure sectors using CONPROSYS HMI System, this vulnerability poses a risk of sensitive information disclosure. Attackers gaining access to phpinfo() output can learn about server configurations, software versions, environment variables, and potentially sensitive credentials or paths. This information can facilitate more sophisticated attacks such as privilege escalation, remote code execution, or lateral movement within networks. While the vulnerability itself does not allow direct system compromise, it lowers the attacker's effort to identify weaknesses. European industries relying on automation and control systems are increasingly targeted by cyber threats, making such information disclosures particularly concerning. The exposure could also lead to compliance issues under regulations like GDPR if sensitive personal or operational data is indirectly exposed. The risk is heightened in environments where network segmentation and access controls are weak, allowing attackers to reach the vulnerable HMI systems from external or less trusted internal networks.

Immediate mitigation steps include restricting access to the phpinfo() debug page by implementing web server access controls such as IP whitelisting, authentication requirements, or disabling the debug page entirely in production environments. Network segmentation should be enforced to isolate HMI systems from general enterprise networks and the internet, limiting exposure to potential attackers. Monitoring and logging access to web interfaces can help detect unauthorized attempts to access debug pages. Organizations should contact Contec Co.,Ltd. for official patches or updates addressing this vulnerability and apply them promptly once available. Additionally, reviewing and hardening PHP configurations to disable unnecessary debug features and removing any development or debug code from production systems is recommended. Conducting regular security assessments and penetration testing on industrial control systems can help identify similar exposures. Finally, educating operational technology (OT) personnel about the risks of exposing debug information and enforcing secure development lifecycle practices will reduce future risks.