CVE-2025-6328 is a critical stack-based buffer overflow vulnerability identified in the D-Link DIR-815 router, specifically version 1.01. The flaw exists within the function sub_403794 of the hedwig.cgi file, which is part of the router's web management interface. An attacker can remotely exploit this vulnerability by sending specially crafted requests to the vulnerable CGI endpoint without requiring authentication or user interaction. The buffer overflow occurs when input data exceeds the allocated stack buffer size, potentially allowing an attacker to overwrite the stack, leading to arbitrary code execution or denial of service. The vulnerability has been publicly disclosed, increasing the risk of exploitation, although no known exploits have been observed in the wild yet. The CVSS 4.0 score of 8.7 (high severity) reflects the vulnerability's ease of remote exploitation (network vector, low attack complexity, no privileges or user interaction required) and its potential to cause significant impact on confidentiality, integrity, and availability. Given the nature of home and small office routers like the DIR-815, successful exploitation could allow attackers to gain control over the device, intercept or manipulate network traffic, pivot to internal networks, or disrupt internet connectivity for affected users.

For European organizations, especially small and medium enterprises (SMEs) and home office setups relying on the D-Link DIR-815 router, this vulnerability poses a significant risk. Compromise of these routers can lead to unauthorized access to internal networks, interception of sensitive communications, and potential lateral movement to other critical systems. This is particularly concerning for sectors with remote workers or distributed offices using this device. The integrity and availability of network infrastructure could be severely impacted, resulting in operational disruptions and data breaches. Additionally, compromised routers could be leveraged as part of botnets or for launching further attacks, amplifying the threat landscape. Given the criticality and remote exploitability without authentication, the vulnerability could be exploited at scale if unmitigated, affecting confidentiality, integrity, and availability of organizational data and services.

1. Immediate firmware update: Organizations and users should verify if D-Link has released a patched firmware version for DIR-815 version 1.01 and apply it promptly. 2. Network segmentation: Isolate vulnerable routers from critical internal networks to limit potential lateral movement in case of compromise. 3. Disable remote management: If remote management via the web interface is enabled, disable it to reduce the attack surface. 4. Monitor network traffic: Implement intrusion detection systems (IDS) or intrusion prevention systems (IPS) to detect anomalous traffic patterns targeting hedwig.cgi or unusual requests to the router's web interface. 5. Replace legacy devices: Consider upgrading to newer router models with active vendor support and security updates, especially for critical organizational environments. 6. Access control: Restrict access to router management interfaces to trusted IP addresses or VPN connections only. 7. Incident response readiness: Prepare for potential incidents by maintaining backups of router configurations and having procedures to quickly isolate and remediate compromised devices.