CVE-2019-14832 in KeyCloak
Summary
by MITRE
A flaw was found in the Keycloak REST API before version 8.0.0 where it would permit user access from a realm the user was not configured. An authenticated attacker with knowledge of a user id could use this flaw to access unauthorized information or to carry out further attacks.
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Analysis
by VulDB Data Team • 01/08/2024
The vulnerability identified as CVE-2019-14832 represents a critical access control flaw within the Keycloak identity and access management platform that affected versions prior to 8.0.0. This issue stems from improper authorization checks within the Keycloak REST API implementation, creating a scenario where authenticated attackers could bypass legitimate access controls and gain unauthorized access to user data across different realms. The flaw specifically manifests when an attacker possesses knowledge of a valid user identifier within a target realm, enabling them to exploit the system's inadequate validation mechanisms.
The technical root cause of this vulnerability aligns with CWE-285, which addresses improper authorization within software systems. Keycloak's REST API failed to properly validate whether an authenticated user had legitimate access rights to specific realms or user resources, creating a path for privilege escalation attacks. The flaw operates by allowing an attacker to make API requests targeting user resources in realms where they have no configured permissions, effectively enabling information disclosure and potential further exploitation. This type of vulnerability is particularly dangerous because it leverages existing authentication credentials rather than requiring additional authentication methods.
The operational impact of CVE-2019-14832 extends beyond simple information disclosure, creating potential pathways for more severe attacks within the affected systems. An authenticated attacker could potentially access sensitive user data, including personal information, authentication tokens, and other confidential details stored within unauthorized realms. This vulnerability directly impacts the principle of least privilege and could enable attackers to escalate their access privileges, potentially leading to full system compromise. The attack vector is particularly concerning because it requires minimal additional information beyond a valid user identifier, making it accessible to attackers who may have gained partial access through other means.
Organizations utilizing Keycloak versions prior to 8.0.0 should implement immediate mitigations including upgrading to the patched version 8.0.0 or later, which includes proper authorization checks and realm validation mechanisms. System administrators should also review and audit existing access controls, ensuring that proper realm-level permissions are enforced and that user access is strictly limited to authorized realms. Network segmentation and monitoring should be implemented to detect anomalous API access patterns that might indicate exploitation attempts. This vulnerability demonstrates the critical importance of proper authorization implementation and serves as a reminder of the potential consequences when access control mechanisms fail to properly validate user permissions and resource boundaries. The ATT&CK framework categorizes this type of vulnerability under privilege escalation and credential access tactics, emphasizing the need for robust access control implementations in identity management systems.