The KRVTZ-NET IDS alerts from 2026-02-02 provide intelligence on network-based reconnaissance and exploit attempts targeting specific vulnerabilities. The key technical detail is the detection of repeated GET requests to the /remote/logincheck endpoint on Fortigate VPN devices, linked to CVE-2023-27997. This CVE describes a vulnerability in Fortigate VPN appliances that could allow unauthorized access or remote code execution if exploited. The alerts also include inbound requests to hidden environment files, which may indicate attempts to gather sensitive configuration data, and HTTP User-Agent scanning from Censys, a known internet scanning service. These activities collectively suggest an adversary performing reconnaissance and preliminary exploitation attempts. No patches are currently available, and no known exploits are confirmed in the wild, indicating the threat is in an early stage. The lack of affected versions and the low severity rating reflect limited immediate risk but highlight the need for vigilance. The indicators of compromise include IP addresses involved in these activities, which can be used for network defense and monitoring. The event is categorized as OSINT and network activity with a kill-chain phase of reconnaissance, emphasizing its role as a precursor to potential attacks.

For European organizations, the primary impact of this threat lies in the potential compromise of Fortigate VPN devices, which are widely used for secure remote access. Successful exploitation of CVE-2023-27997 could lead to unauthorized access, data exfiltration, or disruption of VPN services, affecting confidentiality, integrity, and availability. This could have cascading effects on business continuity, especially for sectors relying heavily on VPNs for remote workforce connectivity, such as finance, healthcare, and government. The reconnaissance activity also increases the risk of targeted attacks by mapping network defenses and identifying vulnerable assets. Although no active exploits are currently confirmed, the presence of scanning and probing activity indicates adversaries are actively seeking to exploit this vulnerability. European organizations with exposed Fortigate VPN endpoints are at elevated risk, and failure to detect or mitigate these attempts could lead to more severe intrusions. The low immediate severity suggests limited current damage, but the potential for escalation warrants proactive defense measures.

European organizations should implement specific mitigations beyond generic advice: 1) Conduct thorough network monitoring focusing on traffic to /remote/logincheck endpoints and unusual inbound requests to hidden files to detect reconnaissance and exploitation attempts early. 2) Restrict external access to Fortigate VPN management interfaces using IP whitelisting, VPN segmentation, or zero-trust network access models to reduce exposure. 3) Deploy intrusion detection and prevention systems (IDS/IPS) with updated signatures to identify CVE-2023-27997 exploitation attempts. 4) Engage with Fortinet support and subscribe to their security advisories to apply patches or workarounds promptly once available. 5) Harden VPN configurations by disabling unnecessary services, enforcing strong authentication, and regularly reviewing logs for anomalies. 6) Conduct internal vulnerability assessments and penetration testing to identify and remediate potential weaknesses related to this vulnerability. 7) Establish incident response plans specifically addressing VPN compromise scenarios to minimize impact if exploitation occurs. 8) Share threat intelligence and indicators of compromise with relevant European cybersecurity communities to enhance collective defense.