CVE-2025-13547 is a memory corruption vulnerability identified in D-Link DIR-822K and DWR-M920 routers running specific firmware versions (1.00_20250513164613 and 1.1.50). The vulnerability is triggered by manipulating the 'submit-url' parameter in the /boafrm/formDdns endpoint, which is part of the router's Dynamic DNS configuration interface. This improper input handling leads to memory corruption, potentially allowing an attacker to execute arbitrary code or cause a denial of service remotely. The vulnerability requires no authentication and no user interaction, making it highly exploitable over the network. The CVSS 4.0 base score of 8.7 reflects the high impact on confidentiality, integrity, and availability, combined with low attack complexity and no privileges required. Although no active exploitation in the wild has been reported, the availability of a public exploit increases the urgency for mitigation. The flaw affects consumer and small business routers commonly deployed in home and office environments, potentially exposing network infrastructure to compromise. The lack of an official patch at the time of publication necessitates interim protective measures to reduce exposure.

For European organizations, exploitation of this vulnerability could lead to unauthorized control over affected routers, enabling attackers to intercept, modify, or disrupt network traffic. This can result in data breaches, network downtime, and facilitate further attacks such as lateral movement into corporate networks. Small and medium enterprises relying on these router models for internet connectivity are particularly at risk, as compromised routers can serve as entry points for attackers. The disruption of availability could impact business operations, especially for organizations with remote or distributed workforces. Confidentiality breaches could expose sensitive corporate or personal data. The vulnerability's remote exploitability without authentication increases the threat level, especially in environments where these devices are directly accessible from the internet. Given the widespread use of D-Link routers in Europe, the potential impact is significant, necessitating urgent attention to mitigation.

1. Immediately check for and apply any firmware updates released by D-Link addressing CVE-2025-13547. 2. If patches are not yet available, restrict access to the router's management interfaces by implementing firewall rules that block inbound traffic to the /boafrm/formDdns endpoint or the router's web management ports from untrusted networks. 3. Segment networks to isolate vulnerable routers from critical infrastructure and sensitive data systems. 4. Monitor network traffic for unusual or suspicious HTTP requests targeting the Dynamic DNS configuration endpoint. 5. Disable Dynamic DNS features if not required to reduce attack surface. 6. Employ intrusion detection/prevention systems capable of recognizing exploit attempts against this vulnerability. 7. Educate IT staff and users about the risk and signs of router compromise. 8. Consider replacing affected devices with models that have confirmed security support if patches are delayed or unavailable.