CVE-2021-36784 in Rancher
Summary
by MITRE • 05/02/2022
A Improper Privilege Management vulnerability in SUSE Rancher allows users with the restricted-admin role to escalate to full admin. This issue affects: SUSE Rancher Rancher versions prior to 2.5.13; Rancher versions prior to 2.6.4.
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Analysis
by VulDB Data Team • 05/04/2022
The vulnerability described in CVE-2021-36784 represents a critical improper privilege management flaw within SUSE Rancher container management platform that directly undermines the principle of least privilege and role-based access control. This security weakness specifically targets the restricted-admin role implementation, allowing attackers with limited administrative privileges to escalate their permissions to full administrative access. The vulnerability exists in the underlying privilege management mechanisms that govern how user roles and permissions are enforced within the Rancher ecosystem, creating a dangerous escalation path that bypasses intended security boundaries.
The technical root cause of this vulnerability stems from inadequate validation and enforcement of privilege boundaries within the Rancher platform's access control system. When users with the restricted-admin role attempt to perform certain administrative operations, the system fails to properly verify whether these actions should be permitted based on their assigned role permissions. This misconfiguration allows privilege escalation through specific API calls or administrative functions that should be restricted to full administrators only. The flaw operates at the application level and affects the core authentication and authorization services that govern user access to Rancher management features and cluster configurations.
From an operational impact perspective, this vulnerability creates a severe risk exposure for organizations relying on SUSE Rancher for container orchestration and management. An attacker who gains access to a restricted-admin account could potentially compromise entire clusters, access sensitive workloads, modify configurations, and escalate their privileges to full administrative control without detection. The vulnerability affects multiple versions of Rancher, including those prior to 2.5.13 and 2.6.4, indicating this was a widespread issue that impacted a significant portion of the user base. Organizations using Rancher for production environments face potential data breaches, service disruptions, and unauthorized access to critical infrastructure components.
Organizations should immediately implement mitigations including upgrading to patched versions of SUSE Rancher where available, implementing additional monitoring and logging of administrative activities, and reviewing existing role assignments to ensure proper privilege separation. The vulnerability aligns with CWE-276, which specifically addresses improper privilege management in software systems, and represents a clear violation of the principle of least privilege that is fundamental to secure system design. From an ATT&CK framework perspective, this vulnerability maps to privilege escalation techniques and could be leveraged by adversaries to move laterally within containerized environments. Security teams should also consider implementing network segmentation, enhanced access controls, and regular privilege audits to detect and prevent unauthorized privilege escalation attempts that could exploit this weakness.