CVE-2017-6393 in NagVis
Summary
by MITRE
An issue was discovered in NagVis 1.9b12. The vulnerability exists due to insufficient filtration of user-supplied data passed to the "nagvis-master/share/userfiles/gadgets/std_table.php" URL. An attacker could execute arbitrary HTML and script code in a browser in the context of the vulnerable website.
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Analysis
by VulDB Data Team • 09/03/2020
The vulnerability identified as CVE-2017-6393 represents a critical cross-site scripting flaw in NagVis version 1.9b12, specifically within the std_table.php gadget component. This issue stems from inadequate input validation mechanisms that fail to properly sanitize user-supplied data before processing and rendering within web interfaces. The vulnerability manifests when malicious input is passed through the affected URL path, allowing attackers to inject arbitrary HTML and JavaScript code that executes in the context of legitimate user sessions. The flaw directly impacts the security posture of systems utilizing NagVis for network monitoring and visualization, potentially enabling attackers to compromise user sessions and execute unauthorized actions.
This vulnerability maps to CWE-79, which specifically addresses Cross-Site Scripting (XSS) conditions where untrusted data is incorporated into web pages without proper validation or escaping. The attack vector exploits the lack of proper output encoding and input sanitization within the NagVis application framework, creating an environment where malicious payloads can be seamlessly integrated into legitimate web content. The vulnerability exists at the application layer where user inputs are not adequately filtered or escaped before being rendered in web browsers, making it particularly dangerous for monitoring systems that often contain sensitive operational data and credentials.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable sophisticated attack chains including session hijacking, credential theft, and data exfiltration. An attacker could craft malicious payloads that redirect users to phishing sites, steal session cookies, or inject backdoors into the monitoring infrastructure. Given that NagVis is commonly used for network infrastructure monitoring, successful exploitation could provide attackers with insights into network topology, operational procedures, and potentially sensitive system configurations. The vulnerability affects both authenticated and unauthenticated users, making it particularly dangerous as it can be exploited without requiring prior access credentials.
Mitigation strategies for CVE-2017-6393 should prioritize immediate patching of the NagVis application to the latest stable version that addresses the XSS vulnerability. Organizations should implement proper input validation and output encoding mechanisms at all points where user data enters the application, particularly within gadget components and dynamic content rendering modules. Network segmentation and web application firewalls can provide additional defense-in-depth layers to detect and prevent exploitation attempts. Regular security assessments of monitoring systems should include vulnerability scanning for similar XSS conditions, and input sanitization should be enforced through proper application frameworks that automatically escape output based on context. The ATT&CK framework categorizes this vulnerability under T1059.007 for Scripting and T1566.001 for Phishing, highlighting the need for comprehensive security measures that address both technical and social engineering aspects of the threat landscape.