CVE-2020-25816 in Vault Enterprise
Summary
by MITRE • 10/04/2020
HashiCorp Vault and Vault Enterprise 1.0 before 1.5.4 have Incorrect Access Control.
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Analysis
by VulDB Data Team • 01/17/2026
HashiCorp Vault and Vault Enterprise versions 1.0 through 1.5.3 contain a critical access control vulnerability that allows unauthorized users to bypass authentication mechanisms and gain elevated privileges. This vulnerability stems from improper validation of access tokens and session management within the vault's authentication system, creating a pathway for malicious actors to escalate their privileges without proper authorization. The flaw exists in the core authentication flow where the system fails to properly verify the authenticity and authorization scope of incoming requests, particularly affecting the token-based access control model that Vault relies upon for securing sensitive data and cryptographic operations. This issue represents a direct violation of the principle of least privilege and undermines the fundamental security architecture that Vault is designed to provide.
The technical implementation of this vulnerability manifests through a flaw in the token validation process where certain API endpoints do not adequately verify whether the requesting entity possesses the necessary permissions to perform specific operations. Attackers can exploit this by crafting malicious requests that leverage existing valid tokens to access restricted functionality, effectively bypassing the normal authorization checks that should prevent such access. The vulnerability is particularly dangerous because it operates at the authentication layer, meaning that successful exploitation allows attackers to gain access to the entire vault infrastructure and potentially compromise all secrets stored within the system. This flaw affects the integrity of Vault's access control matrix and can lead to unauthorized data exposure, modification, or deletion of sensitive cryptographic materials and configuration information.
The operational impact of CVE-2020-25816 extends beyond simple unauthorized access, as it enables attackers to potentially escalate their privileges to administrative levels within the vault environment. Organizations relying on Vault for managing cryptographic keys, sensitive configuration data, and credential storage face significant risk of data breaches and compliance violations. The vulnerability can be exploited through various attack vectors including network-based exploitation and potentially through compromised user accounts, making it particularly challenging to detect and prevent. This weakness directly impacts the security posture of organizations that depend on Vault for their secret management infrastructure, potentially leading to unauthorized access to production systems, user credentials, and other critical organizational assets. The vulnerability also affects Vault Enterprise installations, indicating that the flaw exists in the core architecture rather than being a product of specific enterprise features or configurations.
Organizations should immediately implement mitigation strategies including updating to Vault versions 1.5.4 or later where this vulnerability has been addressed through improved token validation and access control mechanisms. Network segmentation and additional monitoring of authentication endpoints can help detect potential exploitation attempts, while regular security audits of access policies and token usage should be conducted to identify any unauthorized access patterns. The vulnerability aligns with CWE-284 which describes improper access control issues, and maps to ATT&CK technique T1078 for valid accounts and privilege escalation. Security teams should also consider implementing additional authentication layers and regularly rotating access tokens to minimize the impact of potential exploitation. This vulnerability demonstrates the critical importance of maintaining up-to-date security software and the potential consequences of delayed patch management in enterprise security infrastructure.