CVE-2025-54399 is a stack-based buffer overflow vulnerability identified in the Planet WGR-500 router firmware version v1.3411b190912. The vulnerability arises from improper handling of the 'ipaddr' parameter within the formPingCmd functionality, which is used to construct a system command string for ping operations: specifically, the command 'ping -c <counts> <ipaddr> 2>&1 > %s &'. When an attacker sends a series of specially crafted HTTP requests containing maliciously crafted 'ipaddr' values, the input is not properly sanitized or bounds-checked, leading to a stack buffer overflow. This overflow can overwrite the stack memory, potentially allowing an attacker to execute arbitrary code with the privileges of the affected process. The CVSS v3.1 base score is 8.8, reflecting high impact across confidentiality, integrity, and availability, with network attack vector, low attack complexity, and requiring only low privileges without user interaction. The vulnerability is classified under CWE-121 (Stack-based Buffer Overflow). Although no public exploits are currently known, the nature of the flaw and ease of remote exploitation make it a critical concern. The vulnerability affects only the specified firmware version, and no official patches have been linked yet. Attackers could leverage this flaw to gain control over the router, intercept or manipulate network traffic, disrupt network services, or use the device as a pivot point for further attacks.

For European organizations, the impact of CVE-2025-54399 can be severe. Compromise of Planet WGR-500 routers could lead to unauthorized access to internal networks, interception of sensitive data, disruption of network availability, and potential lateral movement within corporate environments. Given the router’s role as a network gateway device, exploitation could undermine network perimeter defenses, affecting confidentiality, integrity, and availability of critical systems. Industries with high reliance on secure and stable network infrastructure, such as finance, healthcare, telecommunications, and government agencies, would be particularly vulnerable. Additionally, disruption of network services could impact operational continuity and compliance with data protection regulations like GDPR. The lack of known exploits in the wild provides a window for proactive defense, but the high CVSS score indicates that successful exploitation would have significant consequences.

1. Immediately restrict access to the router’s management interface by implementing network segmentation and firewall rules to limit HTTP access only to trusted administrative hosts. 2. Disable remote management features if not required, or enforce strong authentication and IP whitelisting. 3. Monitor network traffic for unusual HTTP requests targeting the 'ipaddr' parameter or abnormal ping command patterns. 4. If possible, upgrade to a patched firmware version once released by Planet; in the absence of an official patch, consider temporary device replacement or isolation. 5. Employ intrusion detection/prevention systems (IDS/IPS) with signatures or heuristics to detect exploitation attempts targeting this vulnerability. 6. Conduct regular security audits of network devices and maintain an inventory of affected hardware to prioritize remediation. 7. Educate network administrators about the vulnerability and encourage vigilance for signs of compromise. 8. Consider deploying network-level mitigations such as web application firewalls (WAF) that can filter malicious HTTP requests.