CVE-2025-54402 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 'submit-url' and 'ipaddr' parameters within the formPingCmd functionality, which processes HTTP requests. An attacker can exploit this flaw by sending a sequence of specially crafted HTTP requests that overflow the stack buffer, potentially overwriting return addresses or control data. This can lead to arbitrary code execution on the device with the privileges of the affected process. The vulnerability requires the attacker to have network access to the device and low privileges (PR:L), but no user interaction is needed. The CVSS v3.1 score of 8.8 reflects the critical impact on confidentiality, integrity, and availability, as successful exploitation could allow an attacker to take full control of the router, intercept or manipulate network traffic, or disrupt network services. No patches or official fixes have been released as of the publication date, and no known exploits are currently observed in the wild. The vulnerability is classified under CWE-121 (Stack-based Buffer Overflow), a common and dangerous class of memory corruption bugs. Given the router’s role in network infrastructure, exploitation could have cascading effects on connected systems.

For European organizations, the exploitation of CVE-2025-54402 could have severe consequences. Compromised routers can serve as entry points for attackers to infiltrate internal networks, intercept sensitive communications, or launch further attacks such as lateral movement or data exfiltration. The loss of confidentiality, integrity, and availability of network infrastructure can disrupt business operations, damage reputation, and lead to regulatory non-compliance, especially under GDPR. Critical sectors such as finance, healthcare, government, and telecommunications are particularly vulnerable due to their reliance on secure and stable network connectivity. Additionally, compromised routers could be leveraged to launch distributed denial-of-service (DDoS) attacks against other targets, amplifying the threat landscape. The absence of patches increases the window of exposure, making proactive mitigation essential. Organizations using Planet WGR-500 routers must assess their exposure and implement compensating controls to minimize risk.

1. Immediate network segmentation: Isolate Planet WGR-500 devices from critical network segments to limit attacker movement if compromised. 2. Restrict management access: Limit HTTP management interfaces to trusted IP addresses and consider disabling remote management if not required. 3. Deploy network-based intrusion detection/prevention systems (IDS/IPS) with signatures or anomaly detection tuned to detect malformed HTTP requests targeting formPingCmd parameters. 4. Monitor network traffic for unusual HTTP request patterns involving 'submit-url' and 'ipaddr' parameters. 5. Use firewall rules to block or rate-limit suspicious HTTP requests to the router’s management interface. 6. Engage with the vendor for firmware updates or patches; apply them promptly once available. 7. Consider replacing affected devices with models from vendors with active security support if patching is delayed. 8. Conduct regular security audits and vulnerability scans focusing on network infrastructure devices. 9. Educate network administrators about this vulnerability and signs of exploitation. 10. Maintain up-to-date backups of router configurations to enable rapid recovery if compromise occurs.