CVE-2020-7220 in Vault Enterprise
Summary
by MITRE
HashiCorp Vault Enterprise 0.11.0 through 1.3.1 fails, in certain circumstances, to revoke dynamic secrets for a mount in a deleted namespace. Fixed in 1.3.2.
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Analysis
by VulDB Data Team • 01/24/2020
HashiCorp Vault Enterprise versions 0.11.0 through 1.3.1 contain a critical security vulnerability that affects the proper revocation of dynamic secrets when namespaces are deleted. This vulnerability stems from a failure in the namespace deletion process to properly clean up all associated secrets, creating a persistent security risk. The flaw occurs specifically during the deletion of a namespace that contains mounted secret backends, where dynamic secrets remain accessible even after the namespace has been removed from the system. This behavior violates fundamental security principles of isolation and access control that are essential for maintaining the integrity of sensitive data environments.
The technical implementation of this vulnerability involves the improper handling of namespace cleanup operations within Vault's internal secret management system. When a namespace is deleted, the system should recursively revoke all dynamic secrets associated with mounts within that namespace, ensuring complete removal of access tokens, credentials, and other sensitive material. However, the flaw allows certain dynamic secrets to persist in the system, maintaining their validity and accessibility even though their parent namespace no longer exists. This creates a scenario where unauthorized access could potentially occur through these orphaned secrets, particularly in environments where namespaces are frequently created and destroyed as part of normal operational workflows. The vulnerability manifests through the improper interaction between namespace lifecycle management and secret revocation mechanisms, creating a gap in Vault's access control enforcement.
The operational impact of this vulnerability extends beyond simple credential exposure, as it undermines the core security model of Vault Enterprise's namespace-based isolation. Organizations using Vault in multi-tenant environments or those implementing frequent namespace provisioning and cleanup operations face significant risks from this flaw. The persistence of dynamic secrets after namespace deletion could allow attackers to maintain access to resources that should have been completely isolated and removed. This vulnerability particularly affects systems where automated processes create and destroy namespaces regularly, as the cleanup process may not properly handle all secret types. The risk is compounded in environments where secrets are managed through dynamic mounts that generate time-sensitive credentials, as these orphaned secrets could remain valid for extended periods, potentially enabling data exfiltration or privilege escalation attacks.
Security mitigations for this vulnerability require immediate upgrade to Vault Enterprise version 1.3.2 or later, which includes the necessary fixes to properly revoke dynamic secrets during namespace deletion operations. Organizations should conduct thorough audits of their existing namespace configurations to identify any potentially affected systems and implement immediate revocation of secrets in namespaces that have been deleted. The fix addresses the underlying issue by ensuring that namespace deletion operations properly traverse all mount points and revoke associated dynamic secrets before completing the deletion process. Additionally, security teams should implement monitoring solutions to detect unusual patterns in namespace deletion and secret access that might indicate the presence of orphaned secrets. This vulnerability aligns with CWE-284 Access Control Issues and maps to ATT&CK technique T1550 Use of Cloud Administration Tools, as it enables unauthorized access through improperly cleaned up cloud-based administrative credentials that persist after namespace deletion operations. Organizations should also review their operational procedures to ensure proper namespace lifecycle management and implement automated checks to verify that all secrets are properly revoked during namespace cleanup processes.