The KRVTZ-NET IDS alerts for 2026-02-01 provide insight into network reconnaissance activities primarily targeting Fortinet FortiGate VPN devices. The key technical detail involves repeated GET requests to the /remote/logincheck endpoint, which is associated with CVE-2023-27997, a known vulnerability in FortiGate VPNs that allows unauthenticated attackers to bypass authentication and potentially execute arbitrary commands. Although no active exploitation has been confirmed in this feed, the presence of multiple IPv4 and IPv6 addresses performing these requests suggests scanning campaigns to identify vulnerable devices. Additional indicators include inbound requests to hidden environment files, which may be attempts to gather sensitive configuration data, and web scanning activities using tools such as 'Fuzz Faster U Fool' and HTTP User-Agent scanners, indicating broad reconnaissance efforts. The alerts are categorized as low severity and reconnaissance phase in the kill chain, implying attackers are in the information-gathering stage. No patches or mitigations are directly referenced in the feed, and no known exploits in the wild have been reported. The data originates from CIRCL OSINT Feed, with automated unsupervised detection, and the event is tagged as perpetual OSINT observation. This suggests ongoing monitoring rather than an immediate active threat. The lack of affected versions or CVSS scores limits precise risk quantification, but the focus on FortiGate VPN devices aligns with known vulnerabilities that have been publicly disclosed and patched previously, emphasizing the importance of patch management and monitoring.

For European organizations, the primary impact of this threat lies in the potential for unauthorized access to VPN infrastructure if the vulnerability CVE-2023-27997 is successfully exploited. FortiGate VPN devices are widely used across Europe for secure remote access, making them attractive targets. Successful exploitation could lead to compromise of VPN gateways, enabling attackers to bypass authentication, gain network footholds, and potentially move laterally within corporate networks. This could result in data breaches, disruption of remote access services, and exposure of sensitive internal resources. Even though current activity is reconnaissance and scanning, it signals preparatory steps for more intrusive attacks. Organizations with unpatched or misconfigured FortiGate devices are at higher risk. Additionally, scanning for hidden environment files may expose configuration secrets or credentials if such files are accessible, increasing the risk of further compromise. The low severity rating reflects the current reconnaissance stage, but the potential impact escalates if exploitation occurs. European critical infrastructure, financial institutions, and enterprises relying heavily on Fortinet VPNs are particularly vulnerable due to their reliance on secure remote connectivity.

European organizations should prioritize the following mitigations: 1) Verify and ensure all FortiGate VPN devices are updated with the latest security patches addressing CVE-2023-27997 and related vulnerabilities. 2) Implement strict network segmentation and access controls to limit exposure of VPN management interfaces to trusted networks only. 3) Deploy and tune IDS/IPS systems to detect and block repeated GET requests to /remote/logincheck and other suspicious scanning behaviors. 4) Conduct regular audits of VPN logs to identify anomalous login attempts or scanning activity. 5) Harden web server configurations to prevent access to hidden environment files and sensitive configuration data. 6) Employ multi-factor authentication (MFA) on VPN access to reduce risk from credential compromise. 7) Monitor threat intelligence feeds like CIRCL OSINT for emerging indicators and update detection rules accordingly. 8) Educate security teams on recognizing reconnaissance patterns to enable proactive incident response. 9) Consider implementing rate limiting and CAPTCHA protections on VPN login endpoints to mitigate automated scanning. 10) Review and restrict outbound traffic from VPN devices to prevent lateral movement if compromised. These targeted actions go beyond generic advice by focusing on the specific attack vectors and reconnaissance techniques identified in the alerts.