CVE-2019-3826 in Prometheus
Summary
by MITRE
A stored, DOM based, cross-site scripting (XSS) flaw was found in Prometheus before version 2.7.1. An attacker could exploit this by convincing an authenticated user to visit a crafted URL on a Prometheus server, allowing for the execution and persistent storage of arbitrary scripts.
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Analysis
by VulDB Data Team • 08/08/2023
The vulnerability identified as CVE-2019-3826 represents a critical security flaw in the Prometheus monitoring system that affects versions prior to 2.7.1. This issue manifests as a stored, DOM-based cross-site scripting vulnerability that poses significant risks to systems relying on Prometheus for infrastructure monitoring. The flaw exists within the web interface of Prometheus where user-provided input is not properly sanitized before being rendered in the browser context, creating an environment where malicious scripts can be executed and persistently stored within the application's data structures.
The technical nature of this vulnerability places it under CWE-79 - Improper Neutralization of Input During Web Page Generation, specifically categorized as a stored XSS variant where the malicious payload is first stored on the server and then executed when other users access the affected page. The DOM-based aspect indicates that the vulnerability exploits the Document Object Model manipulation rather than traditional server-side input handling, making it particularly challenging to detect and prevent through conventional security measures. Attackers can craft malicious URLs containing XSS payloads that, when visited by authenticated users, trigger script execution within the victim's browser context, potentially compromising the entire monitoring environment.
The operational impact of CVE-2019-3826 extends beyond simple script execution as it provides attackers with the capability to establish persistent footholds within monitoring systems that are often considered trusted environments. Since Prometheus servers typically contain sensitive operational data, including system metrics, service health information, and potentially credentials stored in configuration files, successful exploitation could lead to complete compromise of monitoring infrastructure. The authenticated user requirement means that attackers must first establish initial access through social engineering or other means to convince legitimate users to visit malicious URLs, but once executed, the stored scripts can persist indefinitely until manually removed or the system is updated. This vulnerability directly aligns with ATT&CK technique T1566.001 - Phishing: Spearphishing Attachment, as it relies on user interaction with malicious URLs to achieve exploitation.
Organizations utilizing Prometheus monitoring systems must implement immediate remediation measures including updating to version 2.7.1 or later, which contains proper input sanitization and validation mechanisms. Additional defensive measures should include implementing strict content security policies to limit script execution capabilities within the Prometheus interface, regular security audits of monitored systems, and user education regarding suspicious URL interactions. Network segmentation and monitoring of Prometheus server access patterns can help detect potential exploitation attempts, while regular penetration testing should verify that no other similar vulnerabilities exist within the monitoring infrastructure. The vulnerability underscores the importance of maintaining up-to-date monitoring tools and implementing comprehensive security controls around privileged access points that serve operational data.