The vulnerability identified as CVE-2025-11098 affects the D-Link DIR-823X router firmware version 250416. It is a command injection flaw located in the /goform/set_wifi_blacklists endpoint, specifically in the handling of the macList parameter. This parameter is used to specify MAC addresses to blacklist on the device's Wi-Fi interface. Due to insufficient input validation or sanitization, an attacker can inject arbitrary shell commands through this parameter. The vulnerability can be exploited remotely over the network without requiring user authentication or interaction, making it accessible to any attacker with network access to the device. Successful exploitation allows execution of arbitrary commands with limited privileges, potentially enabling attackers to manipulate device configuration, disrupt network services, or pivot to other internal systems. The CVSS 4.0 vector indicates network attack vector (AV:N), low attack complexity (AC:L), no authentication required (AT:N), no user interaction (UI:N), and partial impact on confidentiality, integrity, and availability (VC:L, VI:L, VA:L). Although no exploits have been observed in the wild, the public availability of exploit code increases the risk of exploitation. The vulnerability is critical for environments where these routers are deployed, especially in small office/home office (SOHO) and enterprise edge scenarios. The lack of vendor patches at the time of publication necessitates immediate mitigation strategies to reduce exposure.

For European organizations, the impact of CVE-2025-11098 can be significant, particularly for small and medium-sized enterprises (SMEs) and home office users relying on D-Link DIR-823X routers. Exploitation can lead to unauthorized command execution on the router, resulting in potential compromise of network perimeter security. Attackers could alter router configurations, disable security controls, or use the device as a foothold to launch further attacks within the internal network. This could lead to data breaches, interception of sensitive communications, or denial of service conditions affecting business operations. Given the router's role as a gateway device, its compromise undermines the confidentiality, integrity, and availability of connected systems. The medium severity rating reflects partial but meaningful impacts, with the ease of remote exploitation increasing the urgency. Organizations lacking network segmentation or monitoring may be particularly vulnerable. Additionally, the absence of authentication requirements for exploitation broadens the attack surface. The threat is exacerbated by the public disclosure of exploit code, which may facilitate automated attacks or inclusion in botnets targeting vulnerable devices across Europe.

1. Immediate mitigation should focus on restricting network access to the vulnerable /goform/set_wifi_blacklists endpoint by implementing firewall rules or access control lists (ACLs) that block inbound traffic to the router's management interfaces from untrusted networks, especially the internet. 2. Disable remote management features on the router if not required, to reduce exposure. 3. Monitor network traffic for unusual requests targeting the /goform/set_wifi_blacklists path or suspicious command injection patterns. 4. Employ network segmentation to isolate vulnerable devices from critical infrastructure and sensitive data stores. 5. Regularly audit and update router firmware; apply vendor patches as soon as they become available. 6. If vendor patches are delayed, consider replacing affected devices with models that have confirmed security updates. 7. Educate users and administrators about the risks of using default or outdated firmware and the importance of secure configuration. 8. Deploy intrusion detection/prevention systems (IDS/IPS) capable of detecting command injection attempts targeting router management interfaces. 9. Maintain an inventory of network devices to quickly identify and remediate vulnerable units. 10. Collaborate with ISPs or managed security service providers to monitor and block exploit attempts at the network edge.