CVE-2017-5179 in Nessus
Summary
by MITRE
Cross-site scripting (XSS) vulnerability in Tenable Nessus before 6.9.3 allows remote authenticated users to inject arbitrary web script or HTML via unspecified vectors.
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Analysis
by VulDB Data Team • 10/27/2022
The vulnerability identified as CVE-2017-5179 represents a critical cross-site scripting flaw within Tenable Nessus versions prior to 6.9.3, constituting a significant security weakness that affects the widely deployed network security assessment tool. This vulnerability exists within the web interface of Nessus, which is commonly used by security professionals for vulnerability scanning and network assessment activities. The flaw permits remote authenticated attackers to execute malicious code within the context of a victim's browser session, potentially leading to unauthorized access to sensitive information or complete compromise of the affected system.
The technical nature of this XSS vulnerability stems from insufficient input validation and output encoding within the Nessus web application components. Attackers with valid credentials can exploit this weakness by crafting malicious payloads that get executed when other users view affected web pages within the Nessus interface. The unspecified vectors suggest that the vulnerability may manifest across multiple entry points within the web application, making it particularly dangerous as it could be exploited through various user interactions including report generation, configuration settings, or scan result displays. This type of vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws in software applications, where inadequate sanitization of user-supplied data allows malicious scripts to be injected into web pages viewed by other users.
The operational impact of CVE-2017-5179 extends beyond simple data theft, as it can enable attackers to escalate privileges and gain deeper access to the Nessus environment. When security teams rely on Nessus for critical network assessments, an attacker who successfully exploits this vulnerability could potentially access sensitive scan results, modify configuration settings, or even exfiltrate data from the Nessus server itself. The authenticated nature of the exploit means that attackers would need valid user credentials, but this requirement is often met through social engineering, credential theft, or compromised accounts within organizations. This vulnerability directly aligns with ATT&CK technique T1078 which covers valid accounts as a means of gaining access to systems, and T1531 which focuses on account access removal through manipulation of web applications.
Organizations utilizing Nessus should prioritize immediate remediation through patching to version 6.9.3 or later, as this update contains the necessary fixes to address the XSS vulnerability. Additional mitigations include implementing proper web application firewalls, enforcing strict input validation on all user-supplied data, and conducting regular security assessments of web applications to identify similar vulnerabilities. Network segmentation and limiting administrative privileges for Nessus users can also reduce the potential impact of successful exploitation. The vulnerability serves as a reminder of the critical importance of keeping security tools updated, as these applications often serve as prime targets for attackers seeking to gain access to critical network infrastructure and sensitive security data.