CVE-2012-4457 in Keystone
Summary
by MITRE
OpenStack Keystone Essex before 2012.1.2 and Folsom before folsom-3 does not properly handle authorization tokens for disabled tenants, which allows remote authenticated users to access the tenant s resources by requesting a token for the tenant.
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Analysis
by VulDB Data Team • 12/14/2021
The vulnerability described in CVE-2012-4457 represents a critical authorization flaw within OpenStack Keystone authentication services that affected versions prior to specific release milestones. This issue stems from improper token handling mechanisms when dealing with disabled tenants, creating a persistent security weakness that could be exploited by authenticated attackers. The vulnerability specifically impacts the Essex release series before 2012.1.2 and the Folsom release series before folsom-3, indicating a widespread problem affecting multiple OpenStack versions during the early adoption phase of the cloud infrastructure platform.
The technical flaw manifests in the authorization token validation process where Keystone fails to properly verify tenant status when issuing authentication tokens. When a tenant account is disabled, the system should revoke access to all associated resources and prevent token issuance for that tenant. However, the vulnerability allows attackers to obtain valid tokens for disabled tenants, effectively bypassing the intended access controls. This occurs because the token generation process does not adequately check tenant status or maintain proper state information regarding tenant disablement, creating a condition where disabled tenants remain accessible through valid authentication tokens.
The operational impact of this vulnerability extends beyond simple unauthorized access, as it fundamentally undermines the security model of OpenStack deployments. Attackers who gain authenticated access to the system can leverage this weakness to access resources belonging to disabled tenants, potentially compromising sensitive data and system integrity. This vulnerability directly violates the principle of least privilege and could enable attackers to escalate their privileges or access confidential information within the cloud environment. The implications are particularly severe in multi-tenant deployments where proper tenant isolation is critical for maintaining security boundaries.
This vulnerability maps to CWE-284, which addresses improper access control in software systems, and aligns with ATT&CK technique T1078 for valid accounts and T1566 for credential harvesting. The flaw demonstrates a classic authorization bypass where legitimate authentication credentials are used to access resources that should be restricted. Organizations implementing OpenStack infrastructure were particularly vulnerable during the affected time periods, as the issue persisted across multiple releases and affected the core authentication service that all other OpenStack components depend upon for security validation.
Mitigation strategies for CVE-2012-4457 require immediate deployment of the patched versions of OpenStack Keystone that address the token handling logic for disabled tenants. Organizations should implement comprehensive security reviews of their OpenStack deployments to identify and remediate any instances of the vulnerable software versions. The patch mechanisms typically involve updating the Keystone service to properly validate tenant status during token generation and ensure that tokens are not issued for disabled tenants. Additionally, organizations should conduct regular audits of tenant accounts and implement automated monitoring to detect unauthorized access attempts that might exploit this vulnerability, particularly focusing on token issuance patterns and tenant account status changes.