CVE-2021-47697 in Nagios
Summary
by MITRE • 10/31/2025
Nagios XI versions prior to 5.8.0 are vulnerable to cross-site scripting (XSS) via the Views feature URL handling. Insufficient validation or escaping of user-supplied input may allow an attacker to inject and execute arbitrary script in the context of a victim's browser.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 10/31/2025
Nagios XI is a comprehensive network monitoring and management platform that provides real-time visibility into system performance, network health, and application availability. The platform's Views feature serves as a critical component for displaying and organizing monitoring data through customizable dashboards and reports. This feature allows administrators to create and share visual representations of system metrics, making it an essential tool for operational monitoring and incident response. The vulnerability exists within the URL handling mechanism of the Views feature, which processes user-provided parameters to determine what data to display in the monitoring interface. When users navigate to specific views or filter data through URL parameters, the system fails to properly sanitize or validate the input before rendering it in the browser context.
The technical flaw manifests as a cross-site scripting vulnerability that occurs when the system does not adequately escape or validate user-supplied input in URL parameters associated with the Views feature. Attackers can exploit this weakness by crafting malicious URLs containing script code within the view parameters, which are then executed when legitimate users access these crafted links. The vulnerability stems from insufficient input validation and output escaping mechanisms within the web application's parameter processing logic. When the system processes these malformed URLs, it fails to properly encode or sanitize the input data before incorporating it into the HTML response sent to the victim's browser. This allows attackers to inject malicious JavaScript code that executes in the context of the authenticated user's session, potentially leading to full compromise of the monitoring interface.
The operational impact of this vulnerability is significant for organizations relying on Nagios XI for critical infrastructure monitoring. An attacker who successfully exploits this XSS vulnerability can execute arbitrary scripts in the context of any authenticated user's browser session, potentially gaining access to sensitive monitoring data, system configurations, and operational insights. The attack can be particularly dangerous when targeting administrators who have elevated privileges within the Nagios XI environment, as it could enable privilege escalation or data exfiltration. Additionally, the vulnerability may allow attackers to perform session hijacking, redirect users to malicious sites, or manipulate the monitoring data to hide or distort security incidents. The widespread use of Nagios XI across enterprise environments means that a successful exploitation could affect multiple organizations simultaneously, potentially compromising critical network infrastructure monitoring capabilities.
Organizations should immediately upgrade to Nagios XI version 5.8.0 or later, which includes proper input validation and output escaping mechanisms to prevent XSS attacks in the Views feature. System administrators should also implement additional security measures such as web application firewalls that can detect and block malicious script injection attempts. Regular security assessments should include testing for XSS vulnerabilities in all web applications, particularly those handling user-supplied input through URL parameters. The vulnerability aligns with CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting') and maps to ATT&CK technique T1059.007 - Command and Scripting Interpreter: JavaScript, highlighting the exploitation of scripting languages within web browsers. Organizations should also consider implementing Content Security Policy headers to provide additional defense-in-depth against XSS attacks, and conduct regular security training for administrators to recognize potential social engineering attempts that might leverage this vulnerability.