CVE-2011-10039 in Nagios
Summary
by MITRE • 10/31/2025
Nagios XI versions prior to 2011R1.9 are vulnerable to cross-site scripting (XSS) via the Alert Heatmap report and the “My Reports” listing of the web interface. 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 • 11/07/2025
Nagios XI versions prior to 2011R1.9 contain a critical cross-site scripting vulnerability that affects the Alert Heatmap report functionality and the "My Reports" listing within the web interface. This vulnerability stems from inadequate input validation and output escaping mechanisms that fail to properly sanitize user-supplied data before rendering it in web pages. The flaw allows malicious actors to inject malicious scripts that execute in the context of authenticated users' browsers, potentially compromising the security of the entire monitoring infrastructure.
The technical implementation of this vulnerability resides in the web application's failure to properly escape or validate user input within the report generation components. When users interact with the Alert Heatmap report or navigate the "My Reports" section, the application accepts input parameters without sufficient sanitization. This creates an environment where attackers can craft malicious payloads that get executed when other users view the affected reports. The vulnerability specifically targets the web interface components that process and display user-generated content, making it particularly dangerous in environments where multiple administrators access the same monitoring platform.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to escalate privileges, steal session cookies, or perform actions on behalf of authenticated users. An attacker who successfully exploits this vulnerability could potentially access sensitive monitoring data, modify report configurations, or even gain unauthorized access to underlying system resources. The attack vector requires minimal privileges since it targets the web interface rather than requiring system-level access. This makes the vulnerability particularly attractive to threat actors who may already have limited access to the Nagios XI system.
Security professionals should implement immediate mitigations including upgrading to Nagios XI 2011R1.9 or later versions that contain the necessary patches for this vulnerability. Organizations should also consider implementing web application firewalls to detect and block malicious script injection attempts. Input validation should be strengthened across all user-facing web interfaces, particularly those handling report generation and display functions. The vulnerability aligns with CWE-79 which categorizes cross-site scripting flaws, and represents a clear violation of secure coding practices that should be addressed through comprehensive input sanitization and output encoding mechanisms. Additionally, this vulnerability maps to ATT&CK technique T1059.007 for script execution and T1566 for credential access, highlighting the multi-faceted threat potential. Regular security assessments of web applications should include thorough testing of input validation mechanisms to prevent similar vulnerabilities from being introduced in future releases.