CVE-2025-57428 identifies a vulnerability in the Each Italy Wireless Mini Router WIRELESS-N 300M v28K.MiniRouter.20190211 model, where default credentials are used to secure a debug shell accessible via Telnet on port 23. Telnet, an unencrypted protocol, is exposed by default, and the use of default credentials means that attackers can gain unauthenticated remote access to the device's debug interface. Once accessed, attackers can execute commands that manipulate hardware flash memory and device registers, potentially altering firmware or device behavior at a low level. This can lead to persistent compromise, device malfunction, or use of the device as a foothold for further network attacks. The vulnerability is categorized under CWE-284 (Improper Access Control), indicating a failure to restrict access to privileged functions. The CVSS vector (AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N) indicates network attack vector, low attack complexity, no privileges or user interaction required, unchanged scope, and low impact on confidentiality and integrity, with no impact on availability. No patches or known exploits are currently reported, but the presence of default credentials and exposed Telnet service is a well-known risk factor for compromise.

For European organizations, this vulnerability poses a risk of unauthorized access to network infrastructure components, specifically wireless routers used in office or branch environments. Attackers exploiting this vulnerability could manipulate device firmware or configuration, leading to persistent backdoors, interception or redirection of network traffic, and potential lateral movement within corporate networks. Confidentiality and integrity of data passing through affected routers could be compromised. While availability impact is not directly indicated, hardware manipulation could cause device instability or failure. Organizations relying on this router model for critical connectivity or in sensitive environments face increased risk of espionage, data leakage, or disruption. The medium severity suggests a moderate but non-negligible threat, especially in environments where network segmentation or device monitoring is weak. The lack of known exploits currently reduces immediate risk but does not eliminate the threat, as attackers often target devices with default credentials and exposed management interfaces.

European organizations should immediately audit their network infrastructure to identify the presence of Each Italy Wireless Mini Router WIRELESS-N 300M v28K.MiniRouter.20190211 devices. For affected devices, disable Telnet access entirely or restrict it to trusted management networks using firewall rules or VLAN segmentation. Change all default credentials to strong, unique passwords to prevent unauthorized access. If firmware updates or patches become available from the vendor, apply them promptly. Implement network monitoring to detect unusual Telnet connection attempts or unauthorized command execution. Consider replacing vulnerable devices with models that follow modern security best practices, including encrypted management protocols (e.g., SSH instead of Telnet) and robust authentication mechanisms. Additionally, enforce network segmentation to limit the impact of compromised devices and conduct regular security training to raise awareness about default credential risks.