CVE-2009-1076 in Java System Identity Manager
Summary
by MITRE
Sun Java System Identity Manager (IdM) 7.0 through 8.0 responds differently to failed use of the end-user question-based login feature depending on whether the user account exists, which allows remote attackers to enumerate valid usernames.
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Analysis
by VulDB Data Team • 09/02/2019
Sun Java System Identity Manager version 7.0 through 8.0 contains a vulnerability that enables remote attackers to perform user account enumeration through the end-user question-based login feature. This flaw stems from the system's inconsistent response behavior when processing authentication attempts using question-based authentication mechanisms. The vulnerability specifically manifests when attackers attempt to use the question-based login feature with different username inputs, observing varying response times and error messages that reveal whether a particular user account exists within the system.
The technical implementation of this vulnerability falls under the category of information disclosure through timing variations and response differentiation. When a valid user account is targeted, the system processes the question-based authentication request through its legitimate account validation pathways, resulting in a specific response pattern that differs from the response generated when an invalid or non-existent account is targeted. This differential handling creates a side-channel attack vector that adversaries can exploit to distinguish between valid and invalid usernames without requiring any prior knowledge of account credentials.
The operational impact of this vulnerability extends beyond simple account enumeration, as it provides attackers with foundational intelligence for subsequent attack phases. Once valid usernames are identified through this enumeration technique, attackers can leverage this information for targeted brute force attacks, credential stuffing operations, or social engineering campaigns. The vulnerability directly violates security principle of least privilege and information hiding, as it exposes account existence information that should remain confidential to maintain system security posture. This weakness creates an attack surface that aligns with attack techniques described in the MITRE ATT&CK framework under credential access and discovery categories.
The root cause of this vulnerability can be classified as a CWE-209: Information Exposure Through an Error Message, where the system provides different responses based on account existence rather than maintaining consistent error handling behavior. This inconsistency enables attackers to perform account enumeration attacks with minimal effort and maximum effectiveness. The vulnerability affects the authentication mechanism's design and implementation, specifically within the question-based authentication module of the Sun Java System Identity Manager. Security practitioners should note that this vulnerability represents a fundamental flaw in the system's security architecture, as it undermines the principle of security through obscurity that should protect account information from unauthorized discovery.
Organizations utilizing affected versions of Sun Java System Identity Manager should implement immediate mitigations including implementing consistent error handling for all authentication pathways, regardless of account validity, implementing account lockout mechanisms to prevent excessive enumeration attempts, and considering the deployment of additional authentication layers such as multi-factor authentication. The vulnerability also highlights the importance of conducting security assessments of authentication mechanisms to identify similar side-channel vulnerabilities that could expose system information. System administrators should consider implementing rate limiting and monitoring for authentication attempts to detect and prevent automated enumeration attacks. This vulnerability serves as a reminder of the critical importance of consistent security response handling and proper error message design in authentication systems to prevent information leakage that could aid attackers in compromising system security.