CVE-2025-13550 is a buffer overflow vulnerability identified in specific firmware versions (1.00_20250513164613 and 1.1.50) of the D-Link DIR-822K and DWR-M920 routers. The vulnerability resides in an unknown function within the /boafrm/formVpnConfigSetup file, where the submit-url argument is improperly handled, allowing an attacker to overflow a buffer remotely. This flaw does not require authentication or user interaction, making it accessible to remote attackers over the network. Exploiting this vulnerability could allow attackers to execute arbitrary code, potentially gaining control over the affected device or causing a denial of service by crashing the system. The CVSS 4.0 base score is 8.7, reflecting high severity due to network attack vector, low complexity, no privileges or user interaction required, and high impact on confidentiality, integrity, and availability. Although no confirmed exploits have been observed in the wild yet, the public disclosure of the exploit code increases the likelihood of imminent attacks. The vulnerability affects devices commonly used in home and small office environments but can also be found in enterprise settings, especially in Europe where D-Link has a significant market share. The lack of available patches at the time of disclosure necessitates immediate defensive measures to mitigate risk.

The vulnerability poses a significant threat to European organizations using the affected D-Link routers, potentially allowing attackers to remotely execute arbitrary code or disrupt network availability. This can lead to unauthorized access to internal networks, interception or manipulation of sensitive data, and disruption of business operations. Critical infrastructure sectors relying on these devices for VPN or network connectivity could face operational outages or compromise of confidential communications. The high severity and ease of exploitation increase the risk of widespread attacks, especially in environments where these routers are deployed without additional security controls. The impact extends beyond individual devices, as compromised routers can serve as footholds for lateral movement within corporate networks or as platforms for launching further attacks. The absence of patches at disclosure time exacerbates the threat, requiring organizations to implement compensating controls to reduce exposure.

1. Immediately inventory and identify all D-Link DIR-822K and DWR-M920 devices running the vulnerable firmware versions within the network. 2. Monitor D-Link official channels for firmware updates addressing CVE-2025-13550 and apply patches promptly once available. 3. Until patches are released, restrict network access to the vulnerable devices by implementing firewall rules that block inbound traffic to the /boafrm/formVpnConfigSetup endpoint or limit access to trusted IP addresses only. 4. Employ network segmentation to isolate vulnerable routers from critical systems and sensitive data environments. 5. Enable and monitor detailed logging on routers and network devices to detect unusual or suspicious requests targeting the submit-url parameter. 6. Use intrusion detection/prevention systems (IDS/IPS) with updated signatures to identify exploitation attempts. 7. Educate IT staff about this vulnerability and ensure incident response plans include procedures for potential exploitation scenarios. 8. Consider temporary replacement of vulnerable devices with alternative hardware if patching is delayed and risk is unacceptable.