CVE-2025-6371 is a critical stack-based buffer overflow vulnerability found in the D-Link DIR-619L router, specifically version 2.06B01. The flaw exists in the function formSetEnableWizard, located in the /goform/formSetEnableWizard endpoint. This vulnerability arises from improper handling of the 'curTime' argument, which can be manipulated by an attacker to overflow the stack buffer. Such a buffer overflow can lead to arbitrary code execution or cause the device to crash, impacting availability. The vulnerability is remotely exploitable without requiring user interaction or authentication, making it highly dangerous. Although the exploit has been publicly disclosed, there are no known exploits actively used in the wild at this time. Importantly, the affected product is no longer supported by D-Link, meaning no official patches or firmware updates are available to remediate the issue. The CVSS v4.0 score is 8.7 (high severity), reflecting the vulnerability's ease of remote exploitation (network attack vector), lack of required privileges or user interaction, and its potential to severely impact confidentiality, integrity, and availability of the device. The vulnerability affects only the specific firmware version 2.06B01 of the DIR-619L model, which is a consumer-grade wireless router commonly used in home and small office environments. The lack of vendor support and patch availability significantly increases the risk for affected users, as mitigation must rely on alternative controls or device replacement.

For European organizations, the impact of CVE-2025-6371 can be significant, especially for small businesses or home offices that rely on the D-Link DIR-619L router for internet connectivity and network segmentation. Successful exploitation could allow attackers to execute arbitrary code on the router, potentially leading to full compromise of the device. This can result in interception or manipulation of network traffic, loss of confidentiality of sensitive communications, disruption of internet access, and use of the compromised router as a pivot point for further attacks within the network. Given that the device is no longer supported, organizations cannot rely on vendor patches, increasing exposure to persistent threats. The vulnerability also poses risks to availability, as exploitation may cause device crashes or reboots, disrupting business operations. Additionally, compromised routers can be enlisted into botnets, amplifying broader cyber threats. The lack of authentication and user interaction requirements further heightens the risk, as attackers can remotely target vulnerable devices without user awareness. Organizations with limited IT resources or those unaware of the vulnerability may be particularly vulnerable to exploitation.

Since the affected D-Link DIR-619L devices are no longer supported and no official patches exist, mitigation must focus on compensating controls and device replacement. Specific recommendations include: 1) Immediate identification and inventory of all DIR-619L routers running firmware version 2.06B01 within the organization. 2) Replacement of affected devices with currently supported models from reputable vendors that receive regular security updates. 3) If replacement is not immediately feasible, isolate the vulnerable routers by placing them behind additional network security layers such as firewalls or VPNs to restrict remote access to the management interface, especially blocking access to the /goform/formSetEnableWizard endpoint. 4) Disable remote management features on the router to prevent external exploitation. 5) Monitor network traffic for unusual patterns that may indicate exploitation attempts or compromise. 6) Educate users about the risks of using unsupported network equipment and encourage timely hardware upgrades. 7) Employ network segmentation to limit the impact of a compromised router on critical systems. 8) Regularly review and update network device inventories and firmware versions to proactively manage vulnerabilities. These steps go beyond generic advice by focusing on compensating controls tailored to unsupported hardware and emphasizing device replacement as the ultimate mitigation.