CVE-2011-10040 in Nagios
Summary
by MITRE • 10/31/2025
Nagios XI versions prior to 2011R1.9 are vulnerable to cross-site scripting (XSS) via the link-handling functions used by status and report pages. 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.
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Analysis
by VulDB Data Team • 11/08/2025
Nagios XI versions prior to 2011R1.9 contain a critical cross-site scripting vulnerability that affects the link-handling functions utilized in status and report pages. This vulnerability stems from inadequate input validation and output escaping mechanisms within the web interface, creating an attack surface where malicious actors can exploit the system by injecting malicious scripts into user-supplied input fields. The flaw specifically targets the way the application processes and displays links, making it possible for attackers to manipulate the rendering of web content through crafted input parameters.
The technical implementation of this vulnerability allows attackers to execute arbitrary scripts within the context of a victim's browser session, potentially leading to unauthorized access to sensitive information, session hijacking, or further exploitation of the compromised system. This XSS vulnerability operates through the web application's handling of user-supplied data in URL parameters or form fields that are subsequently processed by the status and report page functions. The insufficient sanitization of input data means that malicious payloads can be stored or directly executed when legitimate users view affected pages, creating a persistent threat vector.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with the capability to impersonate legitimate users and access restricted functionality within the Nagios XI environment. This could result in unauthorized access to system monitoring data, configuration changes, or even complete system compromise depending on the privileges of the affected user. The vulnerability affects the core monitoring and reporting capabilities of the application, potentially causing disruption to critical system monitoring operations and creating opportunities for data exfiltration or system manipulation.
Security practitioners should implement immediate mitigations including input validation and output encoding for all user-supplied data, particularly in URL parameters and form fields used by status and report functions. The vulnerability aligns with CWE-79 which classifies cross-site scripting flaws, and follows attack patterns documented in the MITRE ATT&CK framework under techniques related to client-side attacks and credential access. Organizations should prioritize upgrading to Nagios XI 2011R1.9 or later versions that contain proper input validation and sanitization mechanisms. Additional protective measures include implementing web application firewalls, monitoring for suspicious script injection attempts, and conducting regular security assessments of web interfaces to identify similar vulnerabilities in other components of the monitoring infrastructure.