CVE-2011-2477 in Icinga
Summary
by MITRE
Multiple cross-site scripting (XSS) vulnerabilities in config.c in config.cgi in Icinga before 1.4.1, when escape_html_tags is disabled, allow remote attackers to inject arbitrary web script or HTML via a JavaScript expression, as demonstrated by the onload attribute of a BODY element located after a check-host-alive! sequence, a different vulnerability than CVE-2011-2179.
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Analysis
by VulDB Data Team • 11/08/2021
The vulnerability identified as CVE-2011-2477 represents a critical cross-site scripting flaw affecting Icinga monitoring software versions prior to 1.4.1. This vulnerability specifically targets the configuration handling mechanism within the config.cgi component, where the application fails to properly sanitize user input when the escape_html_tags directive is disabled. The flaw resides in the configuration file processing logic that does not adequately filter or escape HTML characters in user-supplied data, creating a persistent vector for malicious code injection.
The technical exploitation of this vulnerability occurs through careful crafting of JavaScript expressions that can be injected into the configuration files processed by config.cgi. Attackers can leverage this weakness by placing malicious JavaScript code within the onload attribute of a BODY element, specifically positioned after a check-host-alive! sequence in the configuration data. This particular injection point demonstrates how the vulnerability operates within the context of Icinga's configuration parsing and rendering pipeline, where unfiltered input flows directly into the web application's output without proper sanitization. The vulnerability is distinct from CVE-2011-2179, indicating separate attack vectors within the same software ecosystem, both stemming from inadequate input validation and output encoding practices.
The operational impact of this vulnerability extends beyond simple script execution, as it enables attackers to perform session hijacking, defacement of monitoring dashboards, and potential data exfiltration from the Icinga environment. When an administrator or user accesses the vulnerable Icinga interface, the malicious JavaScript code embedded in the configuration files executes within the context of the victim's browser, potentially compromising the entire monitoring infrastructure. The vulnerability is particularly dangerous in enterprise environments where Icinga is used for critical infrastructure monitoring, as it could allow attackers to gain unauthorized access to system status information and potentially escalate privileges within the monitoring ecosystem.
Mitigation strategies for CVE-2011-2477 require immediate implementation of the software patch released by Icinga developers in version 1.4.1, which addresses the core configuration handling flaw. Organizations should also implement strict input validation policies for configuration files, ensure that escape_html_tags is enabled by default, and conduct regular security audits of monitoring configuration data. From a cybersecurity perspective, this vulnerability aligns with CWE-79, which describes cross-site scripting flaws, and maps to ATT&CK technique T1059.007 for scripting languages, specifically targeting web application interfaces. Network segmentation and web application firewalls can provide additional layers of protection, though the most effective defense remains the immediate application of vendor patches and adherence to secure coding practices that properly encode output and validate input at all levels of the application stack.