CVE-2025-13190 identifies a critical stack-based buffer overflow vulnerability in the D-Link DIR-816L router firmware version 2_06_b09_beta. The vulnerability resides in the scandir_main function within the /portal/__ajax_exporer.sgi file, where the 'en' argument is improperly validated, allowing an attacker to overwrite the stack memory. This flaw can be triggered remotely without authentication or user interaction, making it highly exploitable. Successful exploitation can lead to arbitrary code execution with elevated privileges on the router, potentially allowing attackers to control the device, intercept or redirect network traffic, or pivot into internal networks. The CVSS 4.0 score of 8.7 reflects the high impact on confidentiality, integrity, and availability, combined with ease of exploitation. Despite the severity, the affected firmware is no longer supported by D-Link, and no official patches are available. Public exploit code has been released, increasing the likelihood of active exploitation. Organizations using this router model with the vulnerable firmware are at significant risk, especially if the device is exposed to untrusted networks. The lack of vendor support necessitates alternative mitigation strategies such as device replacement or network segmentation to reduce exposure.

For European organizations, exploitation of CVE-2025-13190 could result in complete compromise of affected D-Link DIR-816L routers, leading to unauthorized access to internal networks, interception of sensitive communications, and potential lateral movement to other critical systems. This could disrupt business operations, compromise confidential data, and degrade network availability. Given the router’s role as a network gateway, attackers could manipulate traffic or deploy further malware. The absence of vendor patches increases the risk, especially for organizations with legacy infrastructure or limited network segmentation. Critical sectors such as government, finance, and healthcare in Europe could face heightened risks if these devices are deployed in sensitive environments. Additionally, the public availability of exploits lowers the barrier for attackers, including cybercriminals and nation-state actors, to leverage this vulnerability for espionage or sabotage.

Since the affected D-Link DIR-816L firmware version 2_06_b09_beta is no longer supported and no official patches exist, European organizations should prioritize immediate replacement of these devices with supported models running up-to-date firmware. If replacement is not immediately feasible, network administrators should isolate vulnerable routers behind strict firewall rules to restrict access to the management interface and the vulnerable endpoint (/portal/__ajax_exporer.sgi). Implement network segmentation to limit the impact of a compromised router. Monitoring network traffic for unusual activity or exploitation attempts targeting this vulnerability is advised. Employ intrusion detection/prevention systems (IDS/IPS) with signatures for this CVE if available. Disable or restrict remote management interfaces where possible. Regularly audit network devices to identify any remaining vulnerable routers. Finally, educate IT staff about the risks associated with unsupported hardware and the importance of timely device lifecycle management.