CVE-2003-1201 in OpenLDAP
Summary
by MITRE
ldbm_back_exop_passwd in the back-ldbm backend in passwd.c for OpenLDAP 2.1.12 and earlier, when the slap_passwd_parse function does not return LDAP_SUCCESS, attempts to free an uninitialized pointer, which allows remote attackers to cause a denial of service (segmentation fault).
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Analysis
by VulDB Data Team • 06/28/2021
The vulnerability identified as CVE-2003-1201 represents a critical memory management flaw within the OpenLDAP implementation that specifically affects the back-ldbm backend component. This issue manifests in the ldbm_back_exop_passwd function located in the passwd.c file, where the software fails to properly handle error conditions during password processing operations. The flaw occurs when the slap_passwd_parse function returns an error status other than LDAP_SUCCESS, creating a scenario where the system attempts to free an uninitialized memory pointer. This improper memory handling constitutes a classic buffer over-read condition that can be exploited by remote attackers to disrupt service availability.
The technical implementation of this vulnerability stems from inadequate input validation and error handling within the LDAP password modification process. When the slap_passwd_parse function fails to successfully parse incoming password data, it returns an error code that should trigger proper cleanup operations. However, the ldbm_back_exop_passwd function does not properly initialize the pointer variable before attempting to free it, resulting in undefined behavior that manifests as a segmentation fault. This type of vulnerability falls under the CWE-476 category of NULL Pointer Dereference, which is classified as a serious memory safety issue that can lead to system crashes and denial of service conditions. The vulnerability is particularly dangerous because it can be triggered remotely without requiring authentication, making it an attractive target for attackers seeking to disrupt directory services.
The operational impact of this vulnerability extends beyond simple service disruption, as it can be leveraged to create persistent denial of service conditions that affect enterprise directory services. Organizations relying on OpenLDAP 2.1.12 and earlier versions face significant risk when their directory services become unavailable due to this memory corruption issue. The segmentation fault caused by the uninitialized pointer dereference can result in complete service termination, requiring system administrators to restart the LDAP daemon and potentially causing cascading failures in applications that depend on directory services. This vulnerability directly maps to the ATT&CK technique T1499.004 for Network Denial of Service, where adversaries exploit weaknesses in network services to prevent legitimate use of those services. The impact is particularly severe in enterprise environments where directory services are fundamental to authentication, authorization, and identity management operations.
Mitigation strategies for CVE-2003-1201 should focus on immediate patching of affected OpenLDAP installations to version 2.1.13 or later, which contains the necessary fixes for proper pointer initialization and error handling. System administrators should also implement network segmentation and access controls to limit exposure of vulnerable LDAP services to untrusted networks. Additionally, monitoring systems should be configured to detect unusual patterns of service termination or segmentation fault occurrences that may indicate exploitation attempts. The vulnerability demonstrates the critical importance of proper error handling in security-sensitive code, particularly in components that process user input. Organizations should conduct thorough vulnerability assessments of their LDAP implementations and ensure that all directory service components are running patched versions to prevent exploitation of similar memory safety issues that could lead to more severe consequences including arbitrary code execution or privilege escalation attacks.