CVE-2014-4793 in WebSphere MQ
Summary
by MITRE
IBM WebSphere MQ 8.x before 8.0.0.1 does not properly enforce CHLAUTH rules for blocking client connections in certain circumstances related to the CONNAUTH attribute, which allows remote authenticated users to bypass intended queue-manager access restrictions via unspecified vectors.
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Analysis
by VulDB Data Team • 03/25/2018
IBM WebSphere MQ version 8.x prior to 8.0.0.1 contains a critical authorization flaw that undermines the security controls designed to protect queue manager access. This vulnerability specifically affects the CHLAUTH (Channel Authentication) rules implementation, which serves as the primary mechanism for controlling client connections to the messaging system. The flaw manifests when the CONNAUTH attribute is involved in connection processing, creating a scenario where authenticated users can bypass intended access restrictions that should prevent unauthorized client connections. The vulnerability represents a significant deviation from the expected security model where channel authentication rules should enforce strict access controls regardless of user authentication status. This issue falls under the CWE-284 access control weakness category, specifically concerning improper access control enforcement within enterprise messaging systems. The vulnerability enables attackers to escalate privileges and gain unauthorized access to queue manager resources, potentially compromising the entire messaging infrastructure. Attackers can exploit this weakness by establishing authenticated connections and then leveraging the flawed CHLAUTH rule enforcement to bypass intended restrictions, effectively creating backdoor access paths to sensitive queue operations and message data.
The technical implementation of this vulnerability stems from how WebSphere MQ processes channel authentication rules when the CONNAUTH attribute is present in the connection flow. Under normal circumstances, CHLAUTH rules should be enforced consistently to validate client credentials and determine appropriate access levels for each connection attempt. However, the flaw in versions prior to 8.0.0.1 allows certain authenticated connections to proceed without proper authorization validation when CONNAUTH parameters are involved. This creates a scenario where legitimate authentication occurs but the subsequent access control decisions are improperly evaluated, leading to unauthorized access. The vulnerability is particularly concerning because it affects the core authentication and authorization mechanisms that are fundamental to secure messaging operations. From an operational perspective, this weakness can be exploited by both internal and external authenticated users who understand the system's configuration, potentially leading to data breaches, message interception, or disruption of critical messaging services. The impact extends beyond simple unauthorized access as it can enable attackers to perform administrative functions, modify queue configurations, or access sensitive message content that should remain protected. This vulnerability directly relates to the ATT&CK technique T1078 legitimate credentials, where adversaries leverage valid authentication credentials to gain access to systems while bypassing normal access controls.
Organizations using affected WebSphere MQ versions should implement immediate mitigations including upgrading to IBM WebSphere MQ 8.0.0.1 or later, which contains the necessary patches to address the CHLAUTH enforcement flaw. System administrators should also review and validate existing channel authentication rules to ensure that CONNAUTH attributes are properly configured and that no unauthorized access paths exist. Additional defensive measures include implementing network segmentation to limit access to queue manager resources, monitoring connection attempts for unusual patterns, and conducting regular security audits of authentication configurations. The vulnerability demonstrates the critical importance of proper authorization enforcement in enterprise messaging systems and highlights the need for comprehensive security testing of access control mechanisms. Organizations should also consider implementing additional monitoring and alerting for unauthorized connection attempts, as the vulnerability may not be immediately apparent during normal operations. From a compliance standpoint, this vulnerability could impact regulatory requirements for secure messaging systems and may require additional documentation of security controls and remediation efforts. The flaw serves as a reminder of the complexity involved in implementing secure authentication mechanisms and the potential consequences when access control enforcement fails in mission-critical systems.