CVE-2023-22648 in Rancher
Summary
by MITRE • 06/01/2023
A Improper Privilege Management vulnerability in SUSE Rancher causes permission changes in Azure AD not to be reflected to users while they are logged in the Rancher UI. This would cause the users to retain their previous permissions in Rancher, even if they change groups on Azure AD, for example, to a lower privileged group, or are removed from a group, thus retaining their access to Rancher instead of losing it. This issue affects Rancher: from >= 2.6.7 before = 2.7.0 before < 2.7.4.
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Analysis
by VulDB Data Team • 06/25/2023
The vulnerability described in CVE-2023-22648 represents a critical improper privilege management flaw within SUSE Rancher version 2.6.7 through 2.6.9 and 2.7.0 through 2.7.3. This issue stems from a fundamental failure in the authentication and authorization mechanisms that govern how Rancher handles user permissions when integrated with Azure Active Directory. The core problem manifests as a failure to properly synchronize permission changes between the identity provider and the Rancher user interface, creating a persistent security gap that allows users to maintain elevated privileges long after their Azure AD group memberships have been altered or removed.
The technical nature of this vulnerability falls under CWE-284, which specifically addresses improper access control and privilege management issues. When users undergo changes in their Azure AD group memberships such as being moved to lower-privileged groups or completely removed from groups, the Rancher platform fails to invalidate the existing session tokens and refresh the user's permission set within the application. This creates a scenario where users retain access to resources and functionalities they should no longer be authorized to access, effectively bypassing the intended security controls that should automatically revoke access when group membership changes occur. The flaw particularly impacts the session management and token validation processes within the Rancher UI, where the system does not properly implement real-time synchronization of user permissions from the external identity provider.
The operational impact of this vulnerability is severe and directly threatens the principle of least privilege that forms the foundation of secure access management. An attacker who gains access to a user account that has been downgraded in Azure AD but not properly revoked in Rancher could continue to perform administrative actions or access sensitive resources within the Rancher environment. This situation creates a persistent backdoor that could be exploited by both internal and external threat actors, especially if the compromised user account retains elevated privileges while the organization's access control policies have already been updated in the identity provider. The vulnerability essentially creates a time window where the system's access control state becomes inconsistent between the identity provider and the application, leading to potential data breaches, unauthorized access to cluster resources, and violation of security policies that rely on proper group membership management.
Organizations using Rancher in environments where Azure AD integration is critical for access control must implement immediate mitigations to address this vulnerability. The most effective approach involves upgrading to Rancher versions 2.7.4 or later where this issue has been resolved through improved session management and token invalidation mechanisms. Additionally, administrators should consider implementing additional monitoring controls to detect unusual access patterns that might indicate compromised sessions, as well as establishing more frequent manual permission reviews and session invalidation procedures. The vulnerability demonstrates the importance of proper session lifecycle management in multi-tenant and integrated authentication environments, aligning with ATT&CK technique T1566 which covers credential access through compromised credentials and T1078 which addresses valid accounts and legitimate credentials for persistence. Organizations should also consider implementing automated tools to regularly audit and validate user permissions across both the identity provider and application layers to ensure consistency and prevent unauthorized access due to synchronization delays.