CVE-2017-14337 in MISP
Summary
by MITRE
When MISP before 2.4.80 is configured with X.509 certificate authentication (CertAuth) in conjunction with a non-MISP external user management ReST API, if an external user provides X.509 certificate authentication and this API returns an empty value, the unauthenticated user can be granted access as an arbitrary user.
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Analysis
by VulDB Data Team • 12/28/2022
This vulnerability exists in MISP versions prior to 2.4.80 and represents a critical authentication bypass flaw that occurs when the system is configured with X.509 certificate authentication combined with external user management through a REST API. The flaw arises from improper handling of authentication responses when external user data is retrieved through the API. When a user presents a valid X.509 certificate but the external REST API returns an empty or null response for user identification, the system fails to properly validate the authentication state and instead grants access as an arbitrary user account.
The technical implementation of this vulnerability stems from inadequate input validation and authentication flow control within the CertAuth module. When the system receives an X.509 certificate from an external user, it attempts to validate this certificate against the configured external user management API. However, if this API returns an empty value or null response during the user lookup process, the authentication logic does not properly handle this edge case. Instead of rejecting the authentication attempt or requiring additional verification, the system incorrectly interprets the empty response as valid authentication and maps the certificate to a default or arbitrary user account. This creates a privilege escalation scenario where unauthenticated users can gain access to the system with potentially elevated privileges.
The operational impact of this vulnerability is severe as it allows attackers to bypass the intended authentication mechanism entirely. An attacker who can present a valid X.509 certificate can exploit this flaw to gain access to the MISP system and potentially assume the identity of any user account within the system. This represents a direct violation of the principle of least privilege and can lead to unauthorized access to sensitive threat intelligence data, system configuration changes, and potential lateral movement within the network. The vulnerability is particularly dangerous in environments where certificate-based authentication is used for administrative access, as it could allow attackers to gain full administrative privileges.
This vulnerability aligns with CWE-285, which addresses insufficient authorization checks in authentication systems, and relates to ATT&CK technique T1078.004 for valid accounts and T1566 for credential harvesting. The flaw demonstrates poor error handling in authentication flows and inadequate validation of external API responses. Organizations should immediately upgrade to MISP version 2.4.80 or later where this vulnerability has been patched. The mitigation strategy involves ensuring proper validation of external API responses and implementing strict authentication state management. Additionally, organizations should review their certificate-based authentication configurations and ensure that external user management APIs are properly configured to return consistent and valid user data. Network segmentation and monitoring of authentication events should also be implemented to detect and respond to potential exploitation attempts of this vulnerability.