CVE-2025-8169 is a critical buffer overflow vulnerability found in the D-Link DIR-513 router, specifically version 1.10. The flaw exists in the HTTP POST request handler component, within the function formSetWanPPTPcallback located in the /goform/formSetWanPPTPpath endpoint. The vulnerability arises from improper handling of the 'curTime' argument, which can be manipulated by an attacker to cause a buffer overflow. This type of vulnerability can lead to arbitrary code execution, denial of service, or system compromise. The attack can be initiated remotely without authentication or user interaction, making it highly exploitable. Although the CVSS 4.0 score is 8.7 (high severity), the vulnerability affects only an outdated product version that is no longer supported by D-Link, and no official patches have been released. Public exploit code has been disclosed, increasing the risk of exploitation by threat actors. The vulnerability impacts the confidentiality, integrity, and availability of the affected device, potentially allowing attackers to take full control of the router, intercept or manipulate network traffic, or disrupt network connectivity.

For European organizations, the exploitation of this vulnerability could have significant consequences, especially for small and medium enterprises or home offices that still use the D-Link DIR-513 router. Compromise of these devices could lead to unauthorized access to internal networks, interception of sensitive communications, and lateral movement to other internal systems. Given the router's role as a network gateway, attackers could manipulate traffic or launch further attacks against connected devices. Although the device is outdated, some organizations may still rely on it due to budget constraints or lack of awareness. The lack of vendor support means no official patches are available, increasing the risk of prolonged exposure. Additionally, exploitation could disrupt business operations by causing network outages or degraded performance. The public availability of exploit code further elevates the threat level, as less skilled attackers can leverage it to target vulnerable devices.

Since no official patches are available due to the product being out of support, European organizations should prioritize replacing the affected D-Link DIR-513 devices with modern, supported routers that receive regular security updates. In the interim, organizations should restrict remote access to the router's management interface by disabling WAN-side HTTP access or limiting it via firewall rules to trusted IP addresses only. Network segmentation should be implemented to isolate vulnerable devices from critical infrastructure. Monitoring network traffic for unusual activity or signs of exploitation attempts targeting the /goform/formSetWanPPTPpath endpoint is recommended. Employing intrusion detection/prevention systems (IDS/IPS) with signatures for this vulnerability can help detect and block attacks. Organizations should also conduct asset inventories to identify any remaining DIR-513 devices and remove or replace them promptly. User awareness campaigns can help ensure that staff understand the risks of using unsupported hardware.