CVE-2017-8440 in Kibana
Summary
by MITRE
Starting in version 5.3.0, Kibana had a cross-site scripting (XSS) vulnerability in the Discover page that could allow an attacker to obtain sensitive information from or perform destructive actions on behalf of other Kibana users.
Be aware that VulDB is the high quality source for vulnerability data.
Analysis
by VulDB Data Team • 10/13/2019
The vulnerability identified as CVE-2017-8440 represents a critical cross-site scripting flaw within the Kibana web application that affected versions 5.3.0 and later. This vulnerability specifically targeted the Discover page functionality, which serves as a core component for users to explore and analyze data within the Elastic stack ecosystem. The flaw emerged from insufficient input validation and output encoding mechanisms that failed to properly sanitize user-supplied data before rendering it within the web interface. Attackers could exploit this vulnerability by crafting malicious payloads that would be executed in the context of other authenticated users' browsers, potentially enabling unauthorized access to sensitive data and system resources.
The technical implementation of this XSS vulnerability stems from improper handling of user input within the Discover page's data visualization components. When users entered search queries or filtered data sets, the application failed to adequately escape special characters and HTML entities in the rendered output. This allowed malicious scripts embedded within user-provided content to execute in the browser context of other users who viewed the affected data displays. The vulnerability falls under CWE-79 which specifically addresses cross-site scripting flaws where web applications fail to properly validate or escape user input before including it in dynamically generated web pages. The attack vector typically involves an attacker injecting malicious JavaScript code through search parameters or data fields that are then displayed to other users without proper sanitization.
The operational impact of CVE-2017-8440 extends beyond simple data theft, as it could enable attackers to perform destructive actions on behalf of legitimate users. An attacker could potentially execute commands that modify or delete data within Kibana, access restricted administrative functions, or harvest session cookies to maintain persistent access to the system. The vulnerability was particularly concerning because Kibana users often had elevated privileges within their organizations' data environments, making successful exploitation potentially catastrophic for data integrity and confidentiality. This type of vulnerability aligns with ATT&CK technique T1059.007 which covers script-based execution through web applications, and T1566.002 which addresses social engineering via web applications. The risk was amplified by the fact that many organizations used Kibana as a central dashboard for monitoring critical systems and sensitive data, making it an attractive target for cyber adversaries seeking unauthorized access to organizational information.
Organizations affected by this vulnerability should implement immediate mitigations including applying the vendor-provided patches and updates released by Elastic to address the XSS flaw. Additionally, implementing proper input validation and output encoding measures within the application layer would help prevent similar vulnerabilities from emerging in the future. Network segmentation and access controls should be reviewed to limit the potential impact of successful exploitation, while regular security assessments should include thorough testing of web application inputs and outputs. The vulnerability also highlights the importance of following secure coding practices and implementing defense-in-depth strategies that include web application firewalls, content security policies, and regular security training for developers working with web-based applications. Organizations should also consider implementing monitoring solutions that can detect anomalous user behavior patterns that might indicate exploitation attempts against similar vulnerabilities in their infrastructure.