CVE-2014-2237 in Keystone
Summary
by MITRE
The memcache token backend in OpenStack Identity (Keystone) 2013.1 through 2.013.1.4, 2013.2 through 2013.2.2, and icehouse before icehouse-3, when issuing a trust token with impersonation enabled, does not include this token in the trustee's token-index-list, which prevents the token from being invalidated by bulk token revocation and allows the trustee to bypass intended access restrictions.
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Analysis
by VulDB Data Team • 05/09/2026
The vulnerability described in CVE-2014-2237 represents a critical authorization flaw within OpenStack Identity (Keystone) service that affects multiple release versions from 2013.1 through the Icehouse release cycle. This issue specifically targets the memcache token backend implementation where trust tokens are managed, creating a persistent security gap that undermines the integrity of the trust delegation mechanism. The vulnerability stems from improper token management during trust operations, particularly when impersonation is enabled, which creates a fundamental mismatch between token issuance and token tracking within the system's caching layer.
The technical flaw manifests when a trust token is issued with impersonation enabled, as the system fails to properly register this token within the trustee's token-index-list structure. This omission occurs at the memcache level where token metadata is stored and managed for revocation purposes. The consequence is that while the token is successfully issued and can be used for authentication, it becomes invisible to the bulk token revocation mechanisms that rely on maintaining comprehensive token indexes. This architectural oversight creates a scenario where trustees can continue to utilize tokens that should have been invalidated, effectively bypassing the intended access controls that were designed to prevent unauthorized use of delegated privileges.
The operational impact of this vulnerability extends beyond simple access control bypass, as it fundamentally compromises the trust model within OpenStack environments. Attackers or malicious users who gain access to a trust token with impersonation enabled can continue to operate with that token indefinitely, even after the original token should have been revoked or expired. This behavior violates core security principles of least privilege and time-based access control, allowing for prolonged unauthorized access that could escalate to full system compromise. The vulnerability affects organizations using OpenStack deployments where trust delegation is actively employed, particularly in multi-tenant environments where proper access isolation is critical.
Mitigation strategies for this vulnerability require immediate patching of affected OpenStack Identity components to ensure proper token indexing and registration within the memcache backend. Organizations should implement comprehensive token lifecycle management procedures that include regular token auditing and monitoring for anomalous usage patterns. The fix typically involves modifying the token backend implementation to ensure that all trust tokens, regardless of impersonation status, are properly included in the trustee's token-index-list structure. Additionally, security teams should consider implementing enhanced logging and monitoring for trust operations to detect potential misuse of the vulnerability. This issue aligns with CWE-284 Access Control Bypass and ATT&CK techniques related to privilege escalation and credential access, emphasizing the need for robust token management and access control enforcement within cloud infrastructure platforms.