CVE-2025-40629 is a high-severity path traversal vulnerability affecting PNETLab version 4.2.10. The vulnerability arises due to improper sanitization of user-supplied input in the file access mechanisms of the application. Specifically, the application fails to adequately restrict pathname inputs, allowing an attacker to manipulate HTTP request parameters to traverse directories outside the intended restricted directory. This can lead to unauthorized access to sensitive files on the server, potentially exposing configuration files, credentials, or other critical data. The vulnerability is classified under CWE-22 (Improper Limitation of a Pathname to a Restricted Directory), indicating that the software does not properly validate or sanitize file path inputs. According to the CVSS 4.0 vector, the attack vector is network-based (AV:N), requires no privileges (PR:N), no user interaction (UI:N), and no authentication (AT:N). The impact on confidentiality is high (VC:H), while integrity and availability impacts are none (VI:N, VA:N). No known exploits are reported in the wild as of the publication date, but the high CVSS score of 8.7 reflects the ease of exploitation and the potential for significant data exposure. The vulnerability was published on May 16, 2025, and assigned by INCIBE. No official patches or mitigations have been linked yet, emphasizing the need for immediate attention from users of the affected version.

For European organizations using PNETLab 4.2.10, this vulnerability poses a significant risk to the confidentiality of sensitive data. Attackers exploiting this flaw can access files outside the intended directories, potentially leading to exposure of critical configuration files, user credentials, or proprietary information. This can facilitate further attacks such as privilege escalation, lateral movement, or data exfiltration. Given that PNETLab is a network simulation and virtualization platform often used in educational, research, and enterprise environments, the compromise of such systems could disrupt training environments, intellectual property, or network design data. The lack of required authentication and user interaction lowers the barrier for exploitation, increasing the threat level. European organizations with sensitive network infrastructure or research data could face operational disruptions, reputational damage, and regulatory consequences under GDPR if personal or sensitive data is exposed. The absence of known exploits in the wild currently provides a window for proactive mitigation, but the high severity score necessitates urgent action.

1. Immediate upgrade or patching: Organizations should monitor PNETLab vendor announcements for official patches addressing CVE-2025-40629 and apply them as soon as available. 2. Input validation hardening: Until patches are available, implement web application firewalls (WAFs) with custom rules to detect and block directory traversal patterns in HTTP requests targeting PNETLab interfaces. 3. Network segmentation: Restrict access to PNETLab management interfaces to trusted internal networks or VPNs to reduce exposure to external attackers. 4. File system permissions: Harden file system permissions on the server hosting PNETLab to limit the files accessible by the application process, minimizing the impact of traversal attacks. 5. Monitoring and logging: Enable detailed logging of HTTP requests and file access attempts to detect suspicious activity indicative of exploitation attempts. 6. Incident response readiness: Prepare to investigate and respond to potential breaches involving PNETLab systems, including forensic analysis and data recovery plans. 7. User awareness: Inform administrators and users of the affected systems about the vulnerability and the importance of not exposing PNETLab interfaces publicly.