CVE-2025-6090 is a critical buffer overflow vulnerability identified in the H3C GR-5400AX router, specifically affecting version V100R009L50. The flaw resides in the functions UpdateWanparamsMulti and UpdateIpv6params within the /routing/goform/aspForm component. The vulnerability is triggered by the manipulation of the 'param' argument, which leads to a buffer overflow condition. This type of vulnerability can allow an attacker to overwrite memory, potentially enabling arbitrary code execution, denial of service, or system compromise. The vulnerability is remotely exploitable without requiring user interaction or authentication, as indicated by the CVSS vector (AV:N/AC:L/AT:N/UI:N/PR:L). The CVSS 4.0 base score is 8.7, categorizing it as a high-severity issue. Although the vendor acknowledges the vulnerability, they currently assess the risk as low and have no immediate plans for remediation. No official patches have been released, and while public exploit code has been disclosed, there are no confirmed reports of exploitation in the wild. The vulnerability impacts the confidentiality, integrity, and availability of affected devices due to the potential for full system compromise. Given the critical nature of network infrastructure devices like routers, exploitation could lead to network traffic interception, disruption, or lateral movement within enterprise environments.

For European organizations, the exploitation of CVE-2025-6090 poses significant risks, especially for those relying on H3C GR-5400AX routers in their network infrastructure. Successful exploitation could lead to unauthorized access to internal networks, interception or manipulation of sensitive data, and disruption of network services. This is particularly critical for sectors such as telecommunications, finance, government, and critical infrastructure, where network reliability and data confidentiality are paramount. The vulnerability’s remote exploitability without authentication increases the attack surface, making it attractive for threat actors aiming to establish persistent footholds or conduct espionage. Additionally, the lack of an official patch and the vendor’s low-risk assessment may delay mitigation efforts, increasing exposure time. European organizations with limited visibility into their network device firmware versions may inadvertently remain vulnerable. The potential impact extends to supply chain risks if these routers are embedded within managed service providers or third-party network operators serving European clients.

1. Immediate network segmentation: Isolate affected H3C GR-5400AX devices from critical network segments to limit potential lateral movement if compromised. 2. Implement strict access controls: Restrict management interface access to trusted IP addresses and enforce VPN or secure tunnels for remote management. 3. Monitor network traffic for anomalies: Deploy IDS/IPS solutions with signatures or heuristics targeting buffer overflow attempts or unusual traffic patterns directed at the affected functions. 4. Conduct firmware audits: Inventory all network devices to identify those running the vulnerable version V100R009L50 and prioritize their replacement or isolation. 5. Apply compensating controls: Use network-level firewall rules to block or limit access to the vulnerable endpoints (/routing/goform/aspForm) if possible. 6. Engage with the vendor: Maintain communication with H3C for updates or unofficial patches and consider requesting a formal risk reassessment given the public exploit disclosure. 7. Prepare incident response plans: Develop and test procedures for rapid containment and remediation in case exploitation is detected. 8. Consider deploying network behavior anomaly detection tools that can identify exploitation attempts targeting buffer overflow vulnerabilities in routers.