CVE-2025-35021 is a vulnerability classified under CWE-1188, indicating insecure default initialization of resources in the Abilis CPX device. The flaw arises because the device, when unconfigured, allows an attacker to bypass authentication via SSH by failing authentication three times and then gaining access on the fourth attempt to a restricted shell environment. This restricted shell does not provide full administrative control but allows the attacker to relay connections through the device, potentially facilitating unauthorized network access or pivoting attacks. The vulnerability affects version 0 of the product, which likely corresponds to initial or factory default firmware. The CVSS 3.1 base score is 6.5 (medium), reflecting network attack vector (AV:N), low attack complexity (AC:L), no privileges required (PR:N), no user interaction (UI:N), and limited impact on confidentiality and integrity (C:L, I:L), with no impact on availability (A:N). No patches or known exploits are currently reported, but the risk is significant during device provisioning or if devices are reset to factory defaults and exposed on networks. The vulnerability highlights a critical security design flaw where default device state permits unauthorized access without credentials, violating secure initialization principles. Organizations using Abilis CPX devices must be aware of this risk and implement controls to prevent exploitation.

For European organizations, this vulnerability could lead to unauthorized access to network devices during initial deployment or after resets, potentially allowing attackers to relay traffic and gain footholds within internal networks. This can compromise confidentiality and integrity of data passing through or managed by the device. Critical infrastructure providers, telecom operators, and enterprises using Abilis CPX for secure connectivity may face increased risk of lateral movement attacks or data interception. The lack of authentication on unconfigured devices means attackers with network access can exploit this vulnerability remotely without user interaction. While availability is not directly impacted, the indirect effects of unauthorized access could lead to broader security incidents. The vulnerability is particularly concerning in environments with weak network segmentation or insufficient monitoring of device provisioning processes. European organizations must consider the risk to supply chain security and device lifecycle management to prevent exploitation.

1. Ensure all Abilis CPX devices are fully configured and hardened before deployment; never expose unconfigured devices on production networks. 2. Implement strict network segmentation and access control lists (ACLs) to restrict SSH access to trusted management hosts only. 3. Monitor SSH login attempts and alert on repeated failed authentications followed by successful access to restricted shells. 4. Use out-of-band management networks for device provisioning to isolate unconfigured devices from general network traffic. 5. Regularly audit device configurations and reset procedures to prevent accidental exposure of unconfigured devices. 6. Engage with Abilis for firmware updates or patches once available and apply them promptly. 7. Incorporate device initialization checks into security policies and incident response plans to detect and respond to exploitation attempts. 8. Educate network administrators on the risks of default device states and enforce strict operational procedures during device setup.