CVE-2007-6743 in Tivoli Directory Server
Summary
by MITRE
Double free vulnerability in IBM Tivoli Directory Server (TDS) 5.2 before 5.2.0.5-TIV-ITDS-LA0005 allows remote authenticated users to cause a denial of service (ABEND) via search operations that trigger recursive filter_free calls.
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Analysis
by VulDB Data Team • 01/29/2018
The CVE-2007-6743 vulnerability represents a critical double free condition within IBM Tivoli Directory Server version 5.2 prior to 5.2.0.5-TIV-ITDS-LA0005, exposing a significant security flaw that can be exploited remotely by authenticated users to induce system-wide denial of service. This vulnerability specifically manifests during search operations that trigger recursive filter_free function calls, creating a scenario where memory management routines are executed twice on the same memory block, leading to system instability and potential application abend conditions.
The technical flaw stems from improper memory management within the directory server's filter processing mechanism, where the recursive nature of filter_free calls fails to properly track memory allocation states. When an authenticated user crafts specific search queries that result in recursive filter processing, the system's memory deallocation functions execute twice on identical memory segments, causing unpredictable behavior and system crashes. This double free condition falls under the CWE-415 vulnerability category, which specifically addresses double free conditions in memory management operations, making it a well-documented and dangerous class of memory corruption vulnerabilities.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be leveraged to cause sustained denial of service attacks against directory services critical to enterprise authentication and authorization systems. Directory servers serve as foundational components for identity management, and compromising their stability affects the entire organizational infrastructure that relies on proper authentication services. The remote exploitation capability means attackers do not require physical access or local system privileges, making this vulnerability particularly dangerous in enterprise environments where directory services are exposed to network traffic.
From a cybersecurity framework perspective, this vulnerability aligns with ATT&CK technique T1499.004, which covers network denial of service attacks, and demonstrates how memory corruption vulnerabilities can be weaponized for service disruption. The vulnerability also intersects with privilege escalation pathways, as authenticated access is required, but once exploited, the impact can cascade to affect broader system availability. Organizations utilizing IBM Tivoli Directory Server should prioritize immediate patch deployment, as the vulnerability affects core directory service functionality and can be exploited to compromise critical enterprise authentication infrastructure. Mitigation strategies should include network segmentation to limit access to directory services, implementation of intrusion detection systems to monitor for suspicious search operations, and comprehensive testing of patched environments before deployment to ensure no regressions in functionality occur.