Overview
A high-severity security vulnerability, identified as CVE-2025-13357, has been discovered in HashiCorp Vault’s Terraform Provider. This flaw resides within the LDAP auth method configuration and could potentially allow attackers to bypass authentication under specific circumstances. It is highly recommended to upgrade to Vault Terraform Provider v5.5.0 as soon as possible to remediate this issue.
Technical Details
The vulnerability stems from an incorrect default setting for the deny_null_bind parameter in the LDAP auth method configuration within the Vault Terraform Provider. The provider incorrectly defaulted this parameter to false.
If the underlying LDAP server permits anonymous or unauthenticated binds (null binds), setting deny_null_bind to false allows users to potentially bypass authentication. This could grant unauthorized access to Vault secrets and other sensitive data managed by Vault.
CVSS Analysis
This vulnerability has been assigned a CVSS score of 7.4, indicating a high severity. This score reflects the potential impact of a successful exploit, including unauthorized access to sensitive data and systems.
Possible Impact
The impact of exploiting CVE-2025-13357 can be significant:
- Authentication Bypass: Attackers could bypass authentication to Vault using null binds if the LDAP server allows them.
- Unauthorized Access: Successful exploitation could lead to unauthorized access to sensitive secrets and data stored within Vault.
- Data Breach: Compromised credentials could result in a data breach, exposing confidential information.
- Privilege Escalation: Attackers may be able to escalate privileges within the Vault environment, gaining control over sensitive resources.
Mitigation and Patch Steps
To mitigate this vulnerability, immediately upgrade your Vault Terraform Provider to version 5.5.0 or later.
- Upgrade Terraform Provider: Update your Terraform configuration to use Vault Terraform Provider version 5.5.0.
- Verify Configuration: Ensure that the
deny_null_bindparameter is explicitly set totruefor all LDAP auth methods in your Vault configuration. This will prevent authentication bypass via null binds, even if the LDAP server allows them. While upgrading provider versions resolves the issue by setting the proper default, explicitly setting the value offers an added layer of security and clarity. - Review LDAP Server Configuration: As a best practice, review the configuration of your underlying LDAP server to ensure that anonymous binds are disabled wherever possible.
- Test Thoroughly: After applying the patch, thoroughly test your Vault authentication process to ensure that it functions as expected and that no unauthorized access is possible.
