CVE-2005-0899 in AS400
Summary
by MITRE
as/400 running os400 5.2 installs and enables ldap by default which allows remote authenticated users to obtain os/400 user profiles by performing a search.
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Analysis
by VulDB Data Team • 07/22/2017
The vulnerability described in CVE-2005-0899 represents a significant security flaw in IBM AS/400 systems running OS/400 version 5.2 where the Lightweight Directory Access Protocol (LDAP) service is enabled by default. This configuration creates an attack surface that allows remote authenticated users to perform directory searches that can reveal sensitive user profile information from the operating system. The default installation of LDAP functionality without proper access controls or security hardening presents a critical risk to organizations relying on these systems for business operations. The vulnerability specifically affects the authentication and authorization mechanisms of the AS/400 platform, which is designed to provide robust security for enterprise environments.
The technical implementation flaw stems from the default configuration of the LDAP service within the OS/400 operating system where insufficient access controls are implemented to restrict directory search operations. When LDAP is enabled by default, it allows authenticated users to perform search operations against the directory service without proper authorization checks. This means that any user who can authenticate to the system can potentially execute search queries that return user profile information including usernames, group memberships, and potentially other sensitive attributes stored within the directory service. The vulnerability exists at the protocol level where the LDAP implementation does not properly validate or restrict search operations based on user privileges or security contexts.
The operational impact of this vulnerability extends beyond simple information disclosure as it provides attackers with valuable reconnaissance data that can be used for subsequent attacks. An attacker who gains authenticated access to the system can leverage this vulnerability to enumerate user accounts and gather intelligence about the organization's user base. This information can be used to craft targeted attacks, identify high-value targets, or facilitate credential stuffing attacks against other systems. The vulnerability particularly affects environments where the AS/400 system serves as a central directory service or where user authentication is integrated with other enterprise systems, potentially creating cascading security implications across the organization's infrastructure.
Organizations should implement immediate mitigations to address this vulnerability by disabling the LDAP service if it is not required for business operations or by implementing strict access controls and authentication mechanisms. The recommended approach includes reviewing and modifying LDAP configuration settings to ensure that only authorized users can perform directory searches, implementing proper access control lists, and establishing audit logging for directory access operations. Security administrators should also consider implementing network segmentation to limit access to systems running LDAP services and ensure that proper firewall rules are in place to restrict access to these services. This vulnerability aligns with CWE-284 Access Control Issues and can be categorized under ATT&CK technique T1087 Account Discovery, making it a critical target for security hardening efforts. The vulnerability demonstrates the importance of proper security configuration management and the risks associated with default installations of network services that are not properly secured.