CVE-2020-2258 in Health Advisor by CloudBees Plugin
Summary
by MITRE
Jenkins Health Advisor by CloudBees Plugin 3.2.0 and earlier does not correctly perform a permission check in an HTTP endpoint, allowing attackers with Overall/Read permission to view that HTTP endpoint.
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Analysis
by VulDB Data Team • 09/16/2020
The vulnerability identified as CVE-2020-2258 affects the Jenkins Health Advisor plugin developed by CloudBees, specifically versions 3.2.0 and earlier. This security flaw represents a critical permission bypass issue that undermines the access control mechanisms within the Jenkins continuous integration and delivery platform. The vulnerability resides in the plugin's HTTP endpoint implementation where proper authorization checks are not enforced, creating a pathway for unauthorized information disclosure.
The technical root cause of this vulnerability stems from inadequate input validation and permission verification within the plugin's web service endpoints. Attackers with merely Overall/Read permission can exploit this flaw to access sensitive health information that should be restricted to users with higher privileges. This represents a classic case of insufficient authorization controls where the plugin fails to properly validate user credentials against the expected permission levels before exposing sensitive data through its HTTP interface. The vulnerability aligns with CWE-284, which specifically addresses inadequate access control mechanisms, and demonstrates how weak authorization checks can lead to information disclosure attacks.
The operational impact of this vulnerability extends beyond simple information leakage, as it provides attackers with insights into the Jenkins system's health status, configuration details, and potentially sensitive operational data. This information can be leveraged by threat actors to plan more sophisticated attacks against the Jenkins environment, including identifying system weaknesses, understanding the deployment architecture, and potentially discovering other vulnerabilities through the health data exposure. The exposure of health metrics and system diagnostics can reveal critical infrastructure details that would otherwise remain hidden from unauthorized users, creating additional attack vectors and increasing the overall risk posture of the continuous integration environment.
Organizations utilizing affected Jenkins installations should immediately implement mitigations including updating to the patched version of the CloudBees Health Advisor plugin, which resolves the permission validation issue. Network segmentation and firewall rules should be reviewed to limit access to Jenkins endpoints, while security monitoring should be enhanced to detect unauthorized access attempts. The vulnerability demonstrates the importance of proper access control implementation in web applications and highlights how even seemingly minor permission flaws can have significant security implications. Administrators should also consider implementing additional security controls such as role-based access controls, multi-factor authentication, and regular security assessments to prevent similar issues from occurring in other components of their Jenkins infrastructure. This vulnerability serves as a reminder of the critical need for comprehensive security testing and validation of access control mechanisms in enterprise automation platforms.