CVE-2001-1306 in iPlanet Directory Server
Summary
by MITRE
iPlanet Directory Server 4.1.4 and earlier (LDAP) allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via invalid BER length of length fields, as demonstrated by the PROTOS LDAPv3 test suite.
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Analysis
by VulDB Data Team • 06/13/2024
The vulnerability identified as CVE-2001-1306 affects iPlanet Directory Server version 4.1.4 and earlier implementations of the Lightweight Directory Access Protocol. This issue represents a critical security flaw that stems from inadequate validation of Basic Encoding Rules length fields within the LDAP protocol implementation. The vulnerability specifically targets the server's handling of malformed BER (Basic Encoding Rules) length encodings, which are fundamental to how LDAP messages are structured and transmitted. The flaw exists in the server's parsing logic where it fails to properly validate the length field of BER-encoded data structures, creating an exploitable condition that can be leveraged by remote attackers.
The technical exploitation of this vulnerability occurs when an attacker sends specially crafted LDAP requests containing invalid BER length fields to the vulnerable iPlanet Directory Server. These malformed length fields can cause the server to misinterpret memory boundaries or attempt to process data beyond expected limits, resulting in memory corruption. The vulnerability manifests as either a denial of service condition causing the server to crash and restart, or potentially allowing for arbitrary code execution if the memory corruption is sufficiently crafted. The PROTOS LDAPv3 test suite was specifically used to demonstrate this vulnerability, indicating that the issue is well-documented and reproducible through standard LDAP testing frameworks.
From an operational perspective, this vulnerability presents a significant risk to organizations relying on iPlanet Directory Server for directory services and authentication infrastructure. The potential for remote code execution makes this particularly dangerous as it could allow attackers to gain unauthorized access to the directory server and potentially escalate privileges within the network. The denial of service aspect alone can disrupt critical directory services, affecting authentication, authorization, and other directory-dependent applications across the enterprise. The vulnerability affects the core LDAP protocol implementation, making it a fundamental weakness that impacts the entire directory service infrastructure rather than isolated components.
The underlying cause of this vulnerability aligns with CWE-129, which describes improper validation of length fields, and can be mapped to ATT&CK technique T1210 for exploiting weaknesses in remote services. Organizations should immediately implement mitigations including upgrading to patched versions of iPlanet Directory Server, implementing network segmentation to limit access to directory services, and deploying intrusion detection systems to monitor for suspicious LDAP traffic patterns. Additional protective measures include configuring access controls to restrict LDAP query capabilities, implementing rate limiting on directory service requests, and conducting regular security assessments of directory infrastructure components. The vulnerability demonstrates the critical importance of proper input validation in network services and highlights the need for robust BER encoding validation in LDAP implementations.