UnknownPublished 1 Feb 2026

tlp clear · KRVTZ-NET IDS alerts for 2026-02-01

Affects tlp clearSource CIRCL OSINT Feed

TLP:CLEAR, disclosure is not limited

Mentions 1 CVE

Mentioned vulnerabilities

CVE-2023-27997

Description

KRVTZ-NET IDS alerts for 2026-02-01

Impact

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.

Defensive guidance

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.

Indicators of compromise

IP addresses 5

2001:470:1:fb5:199c:a492:95cd:399cET EXPLOIT Fortigate VPN - Repeated GET Requests to /remote/logincheck (CVE-2023-27997)
45.155.68.149ET INFO Request to Hidden Environment File - Inbound
2001:470:1:fb5:6ae2:a7b6:537e:b854ET EXPLOIT Fortigate VPN - Repeated GET Requests to /remote/logincheck (CVE-2023-27997)
103.58.75.88ET SCAN Web Scanner - Fuzz Faster U Fool (Inbound)
199.45.154.130- i Censys - HTTP User-Agent Scanner

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Description

AI analysisMachine-generated, updated 1 Feb 2026, 12:27 UTC

Indicators of compromise

IP addresses 5

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