CVE-2018-1054 in 389-ds-base
Summary
by MITRE
An out-of-bounds memory read flaw was found in the way 389-ds-base handled certain LDAP search filters, affecting all versions including 1.4.x. A remote, unauthenticated attacker could potentially use this flaw to make ns-slapd crash via a specially crafted LDAP request, thus resulting in denial of service.
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Analysis
by VulDB Data Team • 02/17/2023
The vulnerability identified as CVE-2018-1054 represents a critical out-of-bounds memory read flaw within the 389 Directory Server base implementation, specifically affecting the ns-slapd daemon responsible for processing LDAP requests. This issue stems from insufficient input validation when handling certain LDAP search filters, creating a scenario where malformed or specially crafted requests can trigger memory access violations. The flaw impacts all versions of the software including the 1.4.x series, indicating a long-standing issue that has persisted across multiple releases. The vulnerability is particularly concerning because it can be exploited remotely without authentication requirements, making it accessible to any attacker with network connectivity to the affected server.
The technical implementation of this flaw occurs within the LDAP search filter processing logic where the 389-ds-base software fails to properly validate the boundaries of memory allocations when parsing complex filter structures. This allows an attacker to construct malicious LDAP requests that cause the ns-slapd process to attempt reading memory locations beyond the allocated buffer boundaries. The out-of-bounds memory access typically results in segmentation faults or access violations that cause the daemon to crash and restart, leading to service disruption. This type of vulnerability maps directly to CWE-125: Out-of-bounds Read, which is classified as a memory safety issue under the Common Weakness Enumeration framework. The attack pattern aligns with ATT&CK technique T1499.004: Endpoint Denial of Service, specifically targeting service availability through process termination.
The operational impact of CVE-2018-1054 extends beyond simple service disruption as it can be leveraged for sustained denial of service attacks against directory services that rely on 389-ds-base. Organizations utilizing this software for critical directory services, authentication, or identity management may experience significant operational downtime when this vulnerability is exploited. The remote and unauthenticated nature of the attack means that defenders cannot rely on network-level access controls to prevent exploitation, as the vulnerability can be triggered from any network location. This makes the attack surface particularly broad and difficult to defend against in environments where directory services are exposed to untrusted networks. The vulnerability affects enterprise environments that depend on LDAP for authentication and directory services, potentially impacting user access to applications and systems that rely on centralized authentication mechanisms.
Mitigation strategies for CVE-2018-1054 should prioritize immediate patching of affected systems, as the vulnerability has been addressed in subsequent releases of the 389-ds-base software. Organizations should implement network segmentation to limit exposure of directory services to untrusted networks and consider deploying intrusion detection systems to monitor for suspicious LDAP traffic patterns. The implementation of input validation controls and regular security assessments of LDAP service configurations can help identify potential exploitation attempts. Additionally, organizations should maintain comprehensive monitoring of ns-slapd processes for unexpected restarts or crashes that may indicate exploitation attempts. The vulnerability demonstrates the importance of proper memory management in server applications and highlights the need for thorough input validation in network services processing user-supplied data. Organizations should also consider implementing rate limiting and connection throttling mechanisms to reduce the effectiveness of automated exploitation attempts against directory services.