CVE-2025-13549 identifies a critical buffer overflow vulnerability in the D-Link DIR-822K router firmware version 1.00. The flaw exists in the function sub_455524 within the /boafrm/formNtp endpoint, where improper validation of the 'submit-url' parameter allows an attacker to overflow a buffer. This vulnerability is remotely exploitable over the network without requiring authentication or user interaction, making it highly accessible to attackers. The buffer overflow can be leveraged to execute arbitrary code on the device, potentially granting full control over the router. Such control enables attackers to intercept, modify, or disrupt network traffic, pivot into internal networks, or deploy persistent malware. The CVSS 4.0 score of 8.7 reflects the high impact on confidentiality, integrity, and availability, combined with low attack complexity and no privileges required. Although no confirmed exploits are reported in the wild, public proof-of-concept exploits exist, increasing the likelihood of exploitation. The vulnerability affects only firmware version 1.00, so devices running updated firmware may not be vulnerable. However, many organizations may still operate unpatched devices due to update delays or lack of awareness. The lack of available patches at the time of disclosure necessitates immediate mitigation through network controls and monitoring. This vulnerability highlights the risks associated with embedded device firmware flaws and the importance of timely patch management and network segmentation.

For European organizations, exploitation of CVE-2025-13549 could lead to severe consequences including unauthorized remote control of network routers, interception and manipulation of sensitive data, disruption of internet connectivity, and potential lateral movement within corporate networks. Given the router's role as a gateway device, compromise could undermine perimeter defenses and expose internal systems to further attacks. Critical infrastructure sectors relying on these devices may face operational disruptions, data breaches, or espionage risks. The high severity and remote exploitability increase the threat level, especially for SMEs and enterprises that may lack robust network segmentation or monitoring. Additionally, the public availability of exploit code raises the risk of widespread attacks, including ransomware or botnet recruitment campaigns. The impact extends beyond confidentiality to integrity and availability, threatening business continuity and regulatory compliance under frameworks like GDPR. Organizations using DIR-822K routers must assess their exposure and prioritize mitigation to prevent potential damage.

1. Immediately verify the firmware version of all D-Link DIR-822K devices in the network and identify those running version 1.00. 2. Apply any official firmware updates or patches released by D-Link as soon as they become available. 3. If patches are not yet available, restrict access to the router's management interface by implementing network segmentation and firewall rules that block inbound traffic to the /boafrm/formNtp endpoint. 4. Disable remote management features on the router to reduce exposure to external attackers. 5. Monitor network traffic for unusual patterns or attempts to access the vulnerable endpoint, using IDS/IPS solutions with updated signatures. 6. Employ network-level protections such as web application firewalls (WAFs) or reverse proxies to filter malicious requests targeting the vulnerable parameter. 7. Educate IT staff about the vulnerability and ensure incident response plans include steps for potential exploitation scenarios. 8. Consider replacing outdated or unsupported devices with models that receive regular security updates. 9. Conduct regular vulnerability assessments and penetration testing focusing on network infrastructure devices. 10. Maintain an inventory of network devices to quickly identify and remediate vulnerable hardware in the future.