CVE-2018-10554 in Nagios XI
Summary
by MITRE
An issue was discovered in Nagios XI 5.4.13. There is XSS exploitable via CSRF in (1) the Schedule New Report screen via the hour, minute, or ampm parameter, related to components/scheduledreporting; (2) includes/components/xicore/downtime.php, related to the update_pages function; (3) the ajaxhelper.php opts or background parameter; (4) the i[] array parameter to ajax_handler.php; or (5) the deploynotification.php title parameter.
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Analysis
by VulDB Data Team • 02/01/2020
The vulnerability identified as CVE-2018-10554 represents a critical cross-site scripting flaw within Nagios XI 5.4.13 that leverages a combination of persistent and reflected XSS vectors through CSRF exploitation. This vulnerability affects multiple components within the Nagios XI web interface, creating a significant attack surface that could allow malicious actors to execute arbitrary scripts in the context of authenticated users. The flaw stems from inadequate input validation and sanitization of user-supplied parameters across several key modules, including scheduled reporting functionality, downtime management, and ajax handling components.
The technical implementation of this vulnerability occurs through multiple attack vectors that exploit the web application's insufficient parameter validation mechanisms. Attackers can manipulate parameters such as hour, minute, ampm, update_pages, opts, background, i[] array, and title to inject malicious JavaScript code that gets executed when other authenticated users view affected pages. The vulnerability specifically targets the components/scheduledreporting module, includes/components/xicore/downtime.php, ajaxhelper.php, ajax_handler.php, and deploynotification.php, each serving different administrative functions within the Nagios monitoring system. These parameters are processed without proper sanitization, allowing attackers to inject malicious payloads that persist in the application's data storage or are immediately executed upon page rendering.
The operational impact of this vulnerability extends beyond simple script execution, as it enables attackers to perform privilege escalation attacks through session hijacking, data exfiltration, and potential system compromise. An authenticated attacker with access to the Nagios XI interface can leverage this vulnerability to execute arbitrary code on the target system, potentially leading to full system compromise. The attack requires minimal user interaction since the vulnerability is exploitable through CSRF mechanisms, making it particularly dangerous in environments where administrators frequently access the web interface. The persistent nature of some XSS vectors means that malicious scripts can remain active for extended periods, continuously compromising user sessions and potentially exfiltrating sensitive monitoring data.
Mitigation strategies for this vulnerability should focus on implementing comprehensive input validation and output encoding across all user-supplied parameters within the affected components. The recommended approach includes implementing strict parameter validation using whitelisting techniques, applying proper HTML encoding to all dynamic content, and implementing robust CSRF protection mechanisms. Organizations should also consider implementing Content Security Policy headers to prevent script execution, regularly updating Nagios XI to patched versions, and conducting thorough security assessments of web applications. This vulnerability aligns with CWE-79 which specifically addresses cross-site scripting flaws, and maps to ATT&CK technique T1059.007 for command and scripting interpreter execution, as well as T1566 for social engineering through malicious links that could be delivered via the XSS payload. The attack surface is particularly concerning given that Nagios XI is commonly used in enterprise monitoring environments where the compromise of administrative interfaces can lead to widespread system exposure and data breaches.