The KRVTZ-NET IDS alerts from February 21, 2026, report network activity consistent with reconnaissance and exploitation attempts targeting Fortigate VPN devices. Specifically, the alerts identify repeated GET requests to the /remote/logincheck endpoint, which is associated with CVE-2023-27997, a known vulnerability in Fortigate VPN appliances that allows unauthenticated attackers to execute arbitrary code or bypass authentication. The presence of these repeated requests indicates automated scanning or exploitation attempts by threat actors probing for vulnerable Fortigate VPN instances. Additionally, inbound requests to hidden environment files were detected, which may be attempts to access sensitive configuration or environment data that could facilitate further compromise. The alerts are derived from the CIRCL OSINT feed and are tagged as low severity, with no known exploits currently confirmed in the wild and no patches available at the time of reporting. The activity is classified as reconnaissance within the kill chain, suggesting early-stage probing rather than active exploitation or lateral movement. The lack of affected versions and patch information implies that this is an observational report rather than a confirmed vulnerability disclosure. The IP addresses involved are IPv6 addresses linked to the exploit attempts and information gathering. The threat intelligence indicates ongoing scanning activity targeting Fortigate VPN infrastructure, which remains a critical component in many enterprise networks for secure remote access. Organizations should consider these alerts as indicators of potential targeting and take proactive steps to monitor and protect their VPN gateways.

If successful exploitation of CVE-2023-27997 occurs, attackers could gain unauthorized access to Fortigate VPN devices, potentially leading to full system compromise, data exfiltration, and network infiltration. This could undermine the confidentiality, integrity, and availability of enterprise networks relying on these VPNs for secure remote connectivity. Even though current activity is reconnaissance and low severity, persistent exploitation attempts increase the risk of eventual successful breaches. Compromise of VPN infrastructure can facilitate lateral movement, deployment of ransomware, or espionage activities. Organizations worldwide using Fortigate VPNs are at risk, especially those with exposed VPN endpoints accessible from the internet. The impact extends to critical infrastructure, government agencies, and enterprises relying on Fortigate for secure remote access. The reconnaissance activity also indicates that threat actors are actively scanning for vulnerable targets, which could lead to increased attack volume and potential exploitation in the near future. The absence of patches and known exploits in the wild suggests a window of opportunity for attackers to develop or deploy exploits, increasing the urgency for mitigation.

1. Implement strict network segmentation to isolate Fortigate VPN appliances from general network traffic and limit exposure to the internet. 2. Monitor VPN access logs and IDS/IPS alerts for repeated or anomalous requests to /remote/logincheck and other sensitive endpoints. 3. Apply virtual patching or access control lists (ACLs) to block suspicious IP addresses and known malicious traffic patterns targeting Fortigate VPNs. 4. Employ multi-factor authentication (MFA) on VPN access to reduce risk from credential compromise. 5. Regularly audit VPN configurations and disable unused services or endpoints to minimize attack surface. 6. Use threat intelligence feeds to update firewall and IDS signatures to detect exploitation attempts related to CVE-2023-27997. 7. Engage with Fortinet support and security advisories to track patch availability and apply updates promptly once released. 8. Conduct penetration testing and vulnerability assessments focused on VPN infrastructure to identify and remediate weaknesses. 9. Educate security operations teams on recognizing reconnaissance and exploitation indicators specific to Fortigate VPNs. 10. Consider deploying honeypots or deception technologies to detect and analyze attacker behavior targeting VPN endpoints.