CVE-2020-2188 in Amazon EC2 Plugin
Summary
by MITRE
A missing permission check in Jenkins Amazon EC2 Plugin 1.50.1 and earlier in form-related methods allowed users with Overall/Read access to enumerate credentials ID of credentials stored in Jenkins.
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Analysis
by VulDB Data Team • 05/07/2020
The vulnerability identified as CVE-2020-2188 represents a critical authorization flaw within the Jenkins Amazon EC2 Plugin version 1.50.1 and earlier. This issue stems from a missing permission check in form-related methods that govern how credentials are handled within the plugin's interface. The flaw specifically affects the plugin's ability to properly validate user permissions when processing credential enumeration requests, creating an unauthorized access vector that compromises the security of Jenkins credential management systems.
The technical implementation of this vulnerability resides in the plugin's form handling mechanisms where it fails to enforce proper authorization checks before exposing credential identifiers to users with minimal access privileges. This missing permission validation occurs during credential enumeration processes that are typically triggered through web form interactions within the Jenkins interface. The flaw allows attackers with only Overall/Read access rights to discover and extract credential IDs stored within the Jenkins system, effectively bypassing the intended access controls that should restrict such information to users with higher privilege levels.
From an operational perspective, this vulnerability poses significant risks to Jenkins environments that rely on the Amazon EC2 plugin for cloud infrastructure management. The enumeration of credential IDs provides attackers with valuable information that can be used in subsequent attacks targeting the actual credential values or service accounts. This vulnerability directly impacts the principle of least privilege by allowing read-only users to gain unauthorized visibility into sensitive credential infrastructure, potentially enabling credential harvesting attacks that could lead to broader system compromise. The impact extends beyond immediate credential exposure as it undermines the trust model of the Jenkins security architecture and creates opportunities for privilege escalation through additional attack vectors.
Organizations utilizing Jenkins with the affected Amazon EC2 plugin should immediately implement mitigations including updating to the patched version of the plugin, reviewing and tightening access controls, and monitoring for unauthorized credential enumeration attempts. The vulnerability aligns with CWE-284 which addresses improper access control in software systems, and represents a clear violation of the principle of least privilege as defined in cybersecurity best practices. From an ATT&CK framework perspective, this vulnerability maps to techniques involving credential access and privilege escalation, specifically targeting the T1552 and T1078 categories that focus on obtaining and using credentials within compromised environments.
The remediation strategy should prioritize immediate patching of the Amazon EC2 plugin to version 1.51 or later where the missing permission checks have been implemented. Additional defensive measures include implementing network-level restrictions on Jenkins access, enabling multi-factor authentication for administrative functions, and conducting regular security audits of credential storage and access patterns. Organizations should also consider implementing automated monitoring solutions that can detect anomalous credential enumeration activities and alert security teams to potential exploitation attempts. The vulnerability demonstrates the critical importance of proper input validation and authorization checking in web applications, particularly those handling sensitive authentication information.