CVE-2021-37223 : Security Advisory and Response

Nagios Enterprises NagiosXI <= 5.8.4 is affected by a Server-Side Request Forgery (SSRF) vulnerability in schedulereport.php. This vulnerability allows any authenticated user to create scheduled reports with PDF screenshots of any NagiosXI view, potentially leading to unauthorized access to internal resources or disclosure of local system files.

Understanding CVE-2021-37223

This section provides insights into the impact, technical details, and mitigation strategies related to the SSRF vulnerability in NagiosXI.

What is CVE-2021-37223?

The CVE-2021-37223 pertains to an SSRF vulnerability present in Nagios Enterprises NagiosXI <= 5.8.4, enabling authenticated users to generate reports with PDF screenshots that could exploit SSRF to access sensitive resources.

The Impact of CVE-2021-37223

The security flaw in schedulereport.php of NagiosXI <= 5.8.4 poses a significant risk as it allows attackers to manipulate scheduled reports, potentially leading to the unauthorized retrieval of internal data or exposure of system files.

Technical Details of CVE-2021-37223

Let's dive into the specifics of the vulnerability, including its description, affected systems, versions, and exploitation mechanism.

Vulnerability Description

The SSRF vulnerability in schedulereport.php within NagiosXI <= 5.8.4 arises from inadequate input sanitization, facilitating the inclusion of malicious SSRF payloads to exploit legitimate user privileges.

Affected Systems and Versions

All versions of Nagios Enterprises NagiosXI <= 5.8.4 are confirmed to be impacted by this SSRF vulnerability, potentially putting any authenticated user at risk of unauthorized data access.

Exploitation Mechanism

By creating scheduled reports with PDF screenshots using the SSRF payload, malicious actors can bypass security controls and gain access to sensitive internal resources or disclose confidential system files.

Mitigation and Prevention

Discover the immediate steps and long-term security practices to secure your NagiosXI instance against CVE-2021-37223.

Immediate Steps to Take

It is crucial to apply security patches promptly, restrict user access to scheduled reporting functionalities, and monitor for any unauthorized activities to mitigate the risk associated with the SSRF vulnerability.

Long-Term Security Practices

Incorporating robust input validation controls, conducting regular security assessments, and educating users on safe reporting practices are essential for enhancing the overall security posture and preventing SSRF exploits.

Patching and Updates

Stay informed about security updates released by Nagios Enterprises, and ensure timely application of patches to address vulnerabilities like CVE-2021-37223.