CVE-2018-9090 in CoreOS Tectonic
Summary
by MITRE
CoreOS Tectonic 1.7.x and 1.8.x before 1.8.7-tectonic.2 deploys the Grafana web application using default credentials (admin/admin) for the administrator account located at grafana-credentials secret. This occurs because CoreOS does not randomize the administrative password to later be configured by Tectonic administrators. An attacker can insert an XSS payload into the dashboards.
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Analysis
by VulDB Data Team • 12/27/2023
The vulnerability described in CVE-2018-9090 represents a critical security flaw in CoreOS Tectonic versions 1.7.x and 1.8.x prior to 1.8.7-tectonic.2, specifically affecting the Grafana web application deployment within the container orchestration platform. This issue stems from the improper configuration of default administrative credentials that persist throughout the deployment lifecycle, creating an exploitable condition that significantly weakens the overall security posture of the system. The vulnerability manifests through the grafana-credentials secret which contains hardcoded administrative credentials using the well-known default username 'admin' and password 'admin', a pattern that directly aligns with CWE-798, which categorizes the use of hardcoded credentials as a severe security weakness.
The technical exploitation of this vulnerability occurs through cross-site scripting attacks that can be injected into Grafana dashboards, enabling attackers to execute malicious scripts within the context of the victim's browser session. This XSS capability represents a sophisticated attack vector that leverages the weak authentication mechanism to establish a foothold within the monitoring infrastructure. The vulnerability's impact extends beyond simple credential theft, as it allows for full administrative control over the Grafana instance, potentially enabling attackers to manipulate monitoring data, exfiltrate sensitive information, or establish persistent access points within the network infrastructure. The attack surface is further expanded by the fact that Grafana serves as a critical monitoring component in Kubernetes environments, making it a prime target for attackers seeking to gain insights into system operations.
The operational impact of this vulnerability is substantial, as it provides attackers with immediate administrative access to monitoring data and system metrics that are typically considered sensitive. This access can lead to comprehensive reconnaissance of the underlying infrastructure, including identifying running services, network configurations, and potential security gaps within the monitored systems. The persistent nature of the default credentials means that the vulnerability remains exploitable for extended periods without proper patching or configuration updates. Organizations utilizing CoreOS Tectonic in production environments face significant risk of data breaches, system compromise, and potential lateral movement within their network infrastructure. The vulnerability also violates fundamental security principles outlined in the MITRE ATT&CK framework under the credential access and persistence tactics, where attackers can leverage default credentials to establish long-term access to critical monitoring systems.
Mitigation strategies for this vulnerability require immediate action to address the hardcoded credentials and implement proper authentication mechanisms. Organizations should first update their CoreOS Tectonic installations to version 1.8.7-tectonic.2 or later, which resolves the default credential issue through randomized password generation. Additionally, administrators must ensure that all Grafana instances are properly configured with unique administrative credentials and that regular credential rotation policies are implemented. Network segmentation and access controls should be enforced to limit exposure of the Grafana interface to authorized personnel only. The implementation of web application firewalls and input validation mechanisms can help prevent XSS payload injection attempts. Security monitoring should be enhanced to detect suspicious activities within the Grafana interface, including unusual dashboard modifications or unauthorized access attempts. Regular security assessments and penetration testing should be conducted to verify that the remediation measures are effective and that no other similar vulnerabilities exist within the Tectonic platform or related components.