CVE-2025-11099 is a command injection vulnerability identified in the D-Link DIR-823X router firmware version 250416. The vulnerability resides in the uci_del function of the /goform/delete_prohibiting endpoint, where improper sanitization of the delvalue parameter allows an attacker to inject arbitrary shell commands. This flaw can be exploited remotely without requiring authentication or user interaction, making it a significant risk for exposed devices. The vulnerability's 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 the impact is limited (partial compromise), successful exploitation could allow attackers to execute commands with the privileges of the affected process, potentially leading to device takeover, network disruption, or pivoting within internal networks. No public patches have been released yet, and no exploits are known to be active in the wild, but the public disclosure increases the risk of exploitation attempts. The vulnerability affects a widely deployed consumer and small business router model, which is often used in European homes and organizations, increasing the potential attack surface.

For European organizations, this vulnerability poses risks primarily to network infrastructure security and operational continuity. Compromise of the DIR-823X routers could lead to unauthorized access to internal networks, interception or manipulation of network traffic, and disruption of internet connectivity. This could impact confidentiality by exposing sensitive data traversing the network, integrity by allowing attackers to alter configurations or data, and availability by causing denial of service or device instability. Small and medium enterprises, as well as home office setups relying on this router model, are particularly vulnerable due to potentially lax security controls and exposure to the internet. Critical infrastructure entities using these routers for network connectivity could face operational disruptions. The medium severity rating reflects the partial impact and the need for some privileges, but the lack of authentication requirement and remote exploitability increase the threat level. The absence of known exploits in the wild currently limits immediate widespread impact but vigilance is necessary given the public disclosure.

1. Apply firmware updates from D-Link as soon as they become available to address this vulnerability. 2. In the interim, disable remote management interfaces or restrict access to trusted IP addresses only, minimizing exposure to the internet. 3. Implement network segmentation to isolate vulnerable routers from critical systems and sensitive data. 4. Monitor network traffic for unusual command execution patterns or unexpected outbound connections originating from the router. 5. Use intrusion detection/prevention systems (IDS/IPS) to detect exploitation attempts targeting the /goform/delete_prohibiting endpoint. 6. Educate users and administrators about the risks of exposing router management interfaces publicly. 7. Consider replacing affected devices with models that have a stronger security track record if patching is delayed. 8. Regularly audit router configurations and logs to identify signs of compromise or unauthorized changes.