CVE-2026-1741 identifies a backdoor vulnerability in the EFM ipTIME A8004T router firmware version 14.18.2. The flaw resides in the Debug Interface, specifically within the httpcon_check_session_url function located in the /sess-bin/d.cgi file. Attackers can manipulate the 'cmd' argument to trigger unauthorized commands remotely, effectively bypassing authentication and gaining elevated privileges. The attack complexity is rated as high, indicating that exploitation requires advanced knowledge and conditions, including having high privileges on the device. No user interaction is necessary, and the attack vector is network-based, allowing remote exploitation over the internet or local networks. Despite public disclosure, the vendor has not responded or provided patches, leaving affected devices exposed. The vulnerability impacts confidentiality, integrity, and availability by enabling attackers to execute arbitrary commands, potentially leading to full device compromise, data exfiltration, or network disruption. The CVSS 4.0 score of 7.5 reflects the high severity, with high impact on all security properties and requiring high privileges but no user interaction. No known exploits have been observed in the wild yet, but public disclosure increases the risk of future exploitation.

For European organizations, this vulnerability poses significant risks, especially for those relying on EFM ipTIME A8004T routers in their network infrastructure. Successful exploitation could allow attackers to remotely execute arbitrary commands with elevated privileges, leading to unauthorized access to sensitive data, network disruption, or use of the compromised device as a pivot point for lateral movement within corporate networks. Confidentiality breaches could expose customer or proprietary information, while integrity and availability impacts could disrupt business operations. The lack of vendor response and patches increases exposure duration, heightening risk. Organizations in sectors with high security requirements, such as finance, healthcare, and critical infrastructure, are particularly vulnerable. Additionally, the remote attack vector means that devices exposed to the internet or poorly segmented internal networks are at greater risk.

Given the absence of an official patch, European organizations should implement immediate compensating controls. First, restrict access to the router’s management interfaces by limiting IP ranges and enforcing VPN-only access. Disable or restrict the Debug Interface if possible. Employ network segmentation to isolate affected devices from critical assets and sensitive data. Monitor network traffic and device logs for unusual command executions or access patterns related to /sess-bin/d.cgi or suspicious 'cmd' parameters. Regularly audit device firmware versions and configurations to identify affected units. Consider replacing vulnerable devices with models from vendors with active security support if feasible. Engage in threat intelligence sharing to stay informed about emerging exploits. Finally, prepare incident response plans specific to router compromise scenarios to minimize impact if exploitation occurs.