CVE-2025-11096 is a command injection vulnerability identified in the D-Link DIR-823X router, specifically in firmware version 250416. The vulnerability arises from improper sanitization of the target_addr argument in the /goform/diag_traceroute endpoint. This endpoint is designed to perform traceroute diagnostics, but due to insufficient input validation, an attacker can inject arbitrary shell commands. The flaw is remotely exploitable without requiring authentication or user interaction, making it accessible to any attacker who can reach the device's management interface or exposed services. The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P) indicates network attack vector, low attack complexity, no privileges or user interaction needed, and partial impact on confidentiality, integrity, and availability. Although no active exploitation has been reported, a proof-of-concept exploit has been published, increasing the likelihood of future attacks. The vulnerability can lead to full system compromise, allowing attackers to execute arbitrary commands, potentially pivot within networks, exfiltrate sensitive data, or disrupt network operations. The lack of a vendor patch at the time of publication necessitates immediate mitigation steps to reduce exposure.

For European organizations, exploitation of this vulnerability could result in unauthorized remote code execution on affected routers, compromising network perimeter security. This could lead to interception or manipulation of network traffic, disruption of internet connectivity, or use of compromised devices as footholds for lateral movement within corporate networks. Confidentiality risks include data interception and leakage, while integrity and availability could be impacted by malicious command execution causing device malfunction or denial of service. Critical infrastructure operators, SMEs, and enterprises relying on D-Link DIR-823X routers for network access or VPN termination are particularly at risk. The medium CVSS score reflects moderate but tangible risk, especially given the ease of exploitation and lack of authentication. The presence of a public exploit increases the urgency for mitigation to prevent potential targeted attacks or opportunistic scanning by automated tools.

1. Immediately restrict access to the router's management interfaces and the /goform/diag_traceroute endpoint by implementing network segmentation and firewall rules limiting access to trusted IP addresses only. 2. Monitor network traffic for unusual traceroute requests or suspicious command injection patterns targeting the vulnerable endpoint. 3. Disable remote management features if not required, especially WAN-side access to router administration. 4. Apply any available firmware updates from D-Link as soon as they are released addressing this vulnerability. 5. If patches are unavailable, consider replacing affected devices with models not impacted by this vulnerability. 6. Employ intrusion detection/prevention systems (IDS/IPS) with signatures tuned to detect exploitation attempts of this CVE. 7. Conduct regular security audits of network devices to identify and remediate vulnerable firmware versions. 8. Educate IT staff about this vulnerability and ensure incident response plans include steps for router compromise scenarios.