CVE-2000-0747 in OpenLDAP
Summary
by MITRE
The logrotate script for OpenLDAP before 1.2.11 in Conectiva Linux sends an improper signal to the kernel log daemon (klogd) and kills it.
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Analysis
by VulDB Data Team • 04/06/2019
The vulnerability described in CVE-2000-0747 represents a critical flaw in the OpenLDAP logrotate script implementation within Conectiva Linux distributions. This issue stems from an improper signal handling mechanism that directly impacts the kernel log daemon klogd, which serves as a crucial component for managing system logging operations. The logrotate utility, designed to automate log file management and prevent disk space exhaustion, contains a scripting error that causes it to send incorrect signals to klogd during the rotation process. This improper signal delivery results in the termination of the klogd process, effectively disrupting system logging capabilities and potentially compromising the integrity of system monitoring and security auditing functions.
The technical flaw manifests in the logrotate script's handling of klogd signal transmission where the script fails to properly identify or manage the target process, leading to an unintended kill signal being dispatched to the kernel log daemon. This behavior constitutes a signal injection vulnerability that operates outside of normal process management protocols, creating a scenario where legitimate system processes are terminated without proper authorization or context. The flaw specifically affects OpenLDAP versions prior to 1.2.11, indicating a targeted issue within a particular software release that failed to implement proper signal handling procedures. This vulnerability directly relates to CWE-122, which addresses improper handling of signals and process management, and represents a clear violation of proper system administration practices.
The operational impact of this vulnerability extends beyond simple service disruption, as it fundamentally undermines system logging infrastructure that security professionals rely upon for monitoring, incident response, and compliance auditing. When klogd is terminated by the logrotate script, system administrators lose access to kernel-level logging information that is essential for detecting security breaches, system anomalies, and operational issues. The vulnerability creates a window of opportunity for attackers to conduct malicious activities while system logging is disabled, as there is no kernel-level record of their actions. This situation particularly affects environments where OpenLDAP is used for directory services, as the disruption of logging capabilities can mask unauthorized access attempts or configuration changes that should be immediately detected and reported.
Security implications of CVE-2000-0747 align with ATT&CK technique T1070.002, which covers the use of system logs for evasion and disruption of security monitoring. The vulnerability enables adversaries to potentially disable logging mechanisms that would normally detect their activities, creating a stealthy environment for malicious operations. Additionally, the flaw demonstrates characteristics of privilege escalation through service manipulation, as the logrotate script typically runs with elevated privileges during log rotation. Organizations using affected Conectiva Linux versions face significant risk of undetected compromise, as the termination of klogd can occur silently during routine log rotation operations. The vulnerability also impacts system stability and audit readiness, as system administrators cannot rely on complete logging records when this specific condition occurs. Mitigation efforts should focus on immediate patching of OpenLDAP to version 1.2.11 or later, implementing monitoring for klogd process termination, and establishing alternative logging mechanisms to ensure continuous system observability despite potential script failures.