CVE-2024-11390 in Kibana
Summary
by MITRE • 05/01/2025
Unrestricted upload of a file with dangerous type in Kibana can lead to arbitrary JavaScript execution in a victim’s browser (XSS) via crafted HTML and JavaScript files.
The attacker must have access to the Synthetics app AND/OR have access to write to the synthetics indices.
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Analysis
by VulDB Data Team • 05/01/2025
CVE-2024-11390 represents a critical server-side vulnerability within Kibana that enables attackers to upload malicious files with dangerous extensions, potentially leading to cross-site scripting attacks against unsuspecting users. This vulnerability specifically affects the Synthetics application component within Kibana, where unrestricted file upload functionality exists without proper validation of file types or content. The flaw resides in the lack of adequate input sanitization and file type checking mechanisms that should prevent the upload of executable scripts or HTML content that could be interpreted by browsers as legitimate web content.
The technical implementation of this vulnerability stems from insufficient validation controls within the synthetics indices write operations, allowing authenticated attackers with appropriate privileges to bypass normal security restrictions. When an attacker successfully uploads a crafted HTML or JavaScript file through the Synthetics application, the file gets stored in a location accessible to other users within the Kibana environment. The vulnerability is particularly concerning because it leverages the trust relationship between the Kibana application and its users, where legitimate file uploads are expected to be safe for consumption. This creates a scenario where a malicious file uploaded by an attacker can be executed in the browser context of other users who access the synthetics data, effectively enabling a persistent cross-site scripting attack vector.
The operational impact of CVE-2024-11390 extends beyond simple XSS execution to potentially enable more sophisticated attacks including session hijacking, credential theft, and data exfiltration. Attackers can craft malicious files that appear legitimate but contain embedded JavaScript payloads designed to steal cookies, redirect users to malicious sites, or perform actions on behalf of authenticated users. The requirement for access to the Synthetics app or write permissions to synthetics indices creates a privilege escalation scenario where internal attackers or compromised accounts with limited access can gain broader exploitation capabilities. This vulnerability aligns with CWE-434 which specifically addresses the insecure upload of file types that can be interpreted by web browsers, and it maps to ATT&CK technique T1566.001 for credential harvesting through phishing and T1059.007 for JavaScript-based execution within browser environments.
Organizations should implement immediate mitigations including restricting write permissions to synthetics indices, implementing strict file type validation with whitelisting approaches, and deploying content security policies that prevent execution of inline scripts. The vulnerability highlights the importance of principle of least privilege enforcement and proper input validation across all file upload mechanisms within web applications. Security teams should also consider implementing web application firewalls and monitoring for unusual file upload patterns within the Kibana environment. Regular security assessments and penetration testing should focus on identifying similar unrestricted upload vulnerabilities in other application components that may not have been properly secured against malicious file content that could lead to similar cross-site scripting scenarios.