CVE-2025-56498 is an OS command injection vulnerability found in the web management interface of the PLDT WiFi Router model Prolink PGN6401V running Firmware version 8.1.2. The vulnerability exists specifically on the ping6.asp page, which accepts user input through the pingAddr parameter submitted to the /boaform/formPing6 endpoint. This input is not properly sanitized, allowing an authenticated attacker to inject arbitrary system commands. These commands are executed by the underlying operating system with root privileges, effectively granting the attacker full control over the router. The router uses the Boa web server version 0.93.15 to handle HTTP requests, which is implicated in processing the vulnerable endpoint. Exploitation requires authentication, but once achieved, it can lead to complete system compromise, enabling unauthorized control over network traffic, configuration, and potentially pivoting to other devices on the network. Although the CVSS score is 5.3 (medium severity), the impact of root-level command execution on a network device is significant. No public exploits are currently known, and no patches have been linked yet. The vulnerability is classified under CWE-78 (Improper Neutralization of Special Elements used in an OS Command), indicating a failure in input validation and sanitization.

For European organizations, this vulnerability poses a substantial risk to network security and operational continuity. Compromise of a PLDT Prolink PGN6401V router could allow attackers to intercept, manipulate, or redirect network traffic, potentially leading to data breaches or disruption of services. Given the root-level access, attackers could install persistent backdoors, disrupt network connectivity, or use the compromised router as a foothold for lateral movement within the corporate network. This is particularly critical for organizations relying on these routers for perimeter defense or remote office connectivity. The medium CVSS score may underestimate the operational impact since routers are critical infrastructure components. Additionally, unauthorized control over network devices can undermine confidentiality and integrity of communications, which is a significant concern under the EU's GDPR and NIS Directive regulations. The requirement for authentication reduces the attack surface but does not eliminate risk, especially if credentials are weak, reused, or compromised through phishing or other means.

To mitigate this vulnerability, European organizations should first identify any deployment of the PLDT Prolink PGN6401V routers with Firmware 8.1.2 in their network. Immediate steps include restricting access to the router's web management interface to trusted administrators only, ideally through network segmentation and VPN access. Strong, unique passwords must be enforced to prevent unauthorized authentication. Monitoring and logging of administrative access attempts should be enhanced to detect suspicious activity. Since no official patches are currently available, organizations should consider temporary compensating controls such as disabling the vulnerable ping6.asp functionality if possible or replacing affected devices with updated models or firmware versions once available. Network-level protections like firewall rules can limit access to the router management interface from untrusted networks. Regular vulnerability scanning and penetration testing should be conducted to detect exploitation attempts. Finally, educating administrators about the risks of command injection and the importance of secure credential management is essential.