CVE-2020-5790: 
Nagios XI vulnerability analysis and mitigation

Cross-site request forgery (CSRF) vulnerability in Nagios XI 5.7.3 allows a remote attacker to perform sensitive application actions by tricking legitimate users into clicking a crafted link. The vulnerability was discovered in September 2020 and affects the Nagios XI monitoring system version 5.7.3 (Tenable Research).

The CSRF vulnerability exists in various requests within Nagios XI where protection via the Nagios Session Protector is incomplete. Specifically affected components include /nagiosxi/admin/mibs.php and /nagiosxi/includes/components/nxti/index.php. The vulnerability has a CVSS v3 Base Score of 6.5 MEDIUM (Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N) (NVD, Tenable Research).

If exploited, this vulnerability allows an unauthenticated remote attacker to execute sensitive application actions in the context of an authenticated user. The vulnerability can be chained with other vulnerabilities to potentially gain remote code execution capabilities (Tenable Research).

The vulnerability can be exploited by tricking legitimate Nagios users into clicking malicious links through phishing or other social engineering methods. The attack requires user interaction but no special privileges. Proof of concept code demonstrating the vulnerability has been published (Tenable Research).

The recommended mitigation is to upgrade to Nagios XI version 5.7.4 or newer which contains fixes for this vulnerability (Tenable Research).