CVE-2016-9259 in Nessus
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Tenable Nessus before 6.9.1 allows remote authenticated users to inject arbitrary web script or HTML via unspecified vectors.
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Analysis
by VulDB Data Team • 10/04/2022
The CVE-2016-9259 vulnerability represents a critical cross-site scripting flaw within Tenable Nessus versions prior to 6.9.1, exposing organizations to significant web application security risks. This vulnerability specifically affects the Nessus vulnerability scanner, a widely deployed tool used by security professionals for network security assessments and compliance monitoring. The flaw permits remote authenticated attackers to execute malicious scripts within the context of a victim's browser session, potentially compromising the security of the entire scanning environment.
The technical nature of this XSS vulnerability stems from inadequate input validation and output encoding mechanisms within the Nessus web interface. Attackers with valid authentication credentials can exploit this weakness by crafting malicious payloads that get executed when other users view affected pages within the Nessus console. The unspecified vectors suggest that the vulnerability may exist across multiple input points within the application's web interface, making it particularly dangerous as attackers can target various interaction points including scan configurations, report displays, or user management interfaces. This type of vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws in web applications.
The operational impact of CVE-2016-9259 extends beyond simple script injection, as it provides attackers with potential access to sensitive scanning data, user credentials, and system configurations. When an authenticated user navigates to a compromised page or interacts with maliciously crafted scan results, the injected scripts can steal session cookies, redirect users to malicious sites, or even execute arbitrary commands within the context of the Nessus application. This creates a significant risk for organizations relying on Nessus for security assessments, as attackers could potentially gain access to sensitive vulnerability data, scan results, and configuration information that would otherwise remain protected. The vulnerability essentially allows attackers to pivot from the Nessus web interface into potentially more critical system components.
Organizations should immediately upgrade to Nessus version 6.9.1 or later to remediate this vulnerability, as the patch addresses the underlying input validation issues that enabled the XSS attacks. Additionally, implementing proper web application firewall rules, enabling strict content security policies, and conducting regular security assessments of the Nessus installation can help mitigate the risk. The ATT&CK framework categorizes this vulnerability under T1566 - Phishing, as attackers may leverage XSS to deliver malicious payloads to unsuspecting users within the Nessus environment. Security teams should also consider implementing network segmentation, limiting Nessus web interface access to trusted IP ranges, and establishing robust monitoring for suspicious user activities within the scanning environment to detect potential exploitation attempts.