CVE-2025-13549 identifies a buffer overflow vulnerability in the D-Link DIR-822K router, specifically in firmware version 1.00. The vulnerability resides in the function sub_455524 within the /boafrm/formNtp endpoint, which processes the submit-url argument. Improper handling of this argument allows an attacker to overflow a buffer, potentially overwriting adjacent memory. This can lead to arbitrary code execution or cause the device to crash, resulting in denial of service. The vulnerability is remotely exploitable over the network without requiring authentication or user interaction, making it highly accessible to attackers. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:L), no user interaction (UI:N), and high impact on confidentiality, integrity, and availability (VC:H, VI:H, VA:H). Although no active exploitation has been reported, a public exploit is available, increasing the likelihood of attacks. The affected product is a widely used consumer and small office router, often deployed in home and enterprise edge networks. The lack of an official patch at the time of publication necessitates immediate mitigation efforts to prevent exploitation. The vulnerability's presence in a network-facing service increases the risk of widespread compromise, especially in environments where the device is exposed to untrusted networks or the internet.

For European organizations, this vulnerability poses significant risks including unauthorized access, data exfiltration, network disruption, and potential lateral movement within internal networks. Exploitation could lead to full compromise of the affected router, undermining network perimeter defenses and exposing connected devices. Critical infrastructure, small and medium enterprises, and home offices relying on the DIR-822K for internet connectivity or VPN services are particularly vulnerable. The high impact on confidentiality, integrity, and availability means sensitive data could be intercepted or manipulated, and network availability could be disrupted, affecting business continuity. The remote and unauthenticated nature of the exploit increases the threat surface, especially for organizations with inadequate network segmentation or exposed management interfaces. Given the public availability of an exploit, the window for attackers to leverage this vulnerability is open, potentially leading to targeted attacks or widespread scanning and exploitation campaigns across Europe.

1. Immediately check for and apply any official firmware updates from D-Link addressing CVE-2025-13549. 2. If no patch is available, restrict access to the router’s management interface by implementing network-level controls such as firewall rules limiting access to trusted IP addresses only. 3. Disable remote management features or services that expose the vulnerable endpoint to untrusted networks. 4. Employ network intrusion detection and prevention systems (IDS/IPS) with signatures or heuristics capable of detecting exploitation attempts targeting the submit-url parameter. 5. Regularly audit and monitor router logs for unusual activity or repeated malformed requests to /boafrm/formNtp. 6. Segment critical network assets behind additional layers of security to reduce the impact of a compromised router. 7. Educate IT staff on the vulnerability and ensure rapid incident response capabilities are in place. 8. Consider replacing affected devices with models from vendors with more timely security updates if patching is delayed.