CVE-2023-22650 in Rancher
Summary
by MITRE • 10/16/2024
A vulnerability has been identified in which Rancher does not automatically clean up a user which has been deleted from the configured authentication provider (AP). This characteristic also applies to disabled or revoked users, Rancher will not reflect these modifications which may leave the user’s tokens still usable.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 10/16/2024
The vulnerability described in CVE-2023-22650 represents a critical authorization and authentication management flaw within the Rancher container management platform. This issue stems from Rancher's failure to properly synchronize user account lifecycle events with its internal user management system, creating a persistent security gap that can be exploited by malicious actors. The vulnerability specifically affects Rancher's integration with external authentication providers, where user accounts are managed outside of the Rancher platform itself. When users are deleted, disabled, or revoked from the upstream authentication provider, Rancher maintains stale user records in its system, which can lead to continued access privileges and potential unauthorized system interactions.
This authentication bypass vulnerability operates through a fundamental mismatch between external authentication state and internal Rancher user state management. The flaw allows for what is known as a "privilege escalation" or "access token persistence" issue where deleted or disabled users retain access to Rancher resources through valid authentication tokens that were issued prior to their account removal from the authentication provider. The technical implementation fails to properly implement a user lifecycle synchronization mechanism that would automatically invalidate or remove user accounts from Rancher's internal database when corresponding changes occur in the external authentication system. This creates a window of opportunity where compromised or malicious accounts can continue to operate within the Rancher environment long after they should have been removed from system access.
The operational impact of this vulnerability extends beyond simple unauthorized access to encompass potential data breaches, system compromise, and violation of security best practices. Organizations relying on Rancher for container orchestration and management face significant risk when this vulnerability exists, as it undermines the principle of least privilege and creates persistent backdoors within their containerized infrastructure. The vulnerability can be exploited by attackers who gain access to valid tokens from deleted users, potentially allowing them to execute commands, access sensitive data, or manipulate container workloads. This issue directly impacts the integrity and confidentiality of containerized environments, particularly in multi-tenant deployments where proper user isolation is critical. The vulnerability also affects compliance requirements for access control and audit trails, as system administrators cannot rely on Rancher's user management to accurately reflect the current state of authentication providers.
Mitigation strategies for this vulnerability must address both immediate remediation and long-term architectural improvements. Organizations should implement manual cleanup procedures to remove stale user accounts from Rancher's internal database, though this approach is reactive rather than preventive. The recommended solution involves configuring Rancher to periodically synchronize with external authentication providers and automatically invalidate user accounts that no longer exist in the upstream system. This aligns with the security principle of defense in depth and addresses the underlying CWE-284 (Improper Access Control) and CWE-668 (Improper Control of a Resource Through its Lifetime) vulnerabilities. System administrators should also implement robust monitoring and alerting for user account lifecycle events, ensuring that any unauthorized access attempts using stale tokens are immediately detected. Additionally, organizations should consider implementing token rotation policies and short-lived authentication tokens to minimize the window of opportunity for exploitation. The ATT&CK framework categorizes this vulnerability under T1078 (Valid Accounts) and T1531 (Account Access Removal), highlighting the need for both account management controls and continuous monitoring to prevent unauthorized persistence within containerized environments.