CVE-2017-2668 in 389-ds-base
Summary
by MITRE
389-ds-base before versions 1.3.5.17 and 1.3.6.10 is vulnerable to an invalid pointer dereference in the way LDAP bind requests are handled. A remote unauthenticated attacker could use this flaw to make ns-slapd crash via a specially crafted LDAP bind request, resulting in denial of service.
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Analysis
by VulDB Data Team • 03/28/2023
The vulnerability identified as CVE-2017-2668 affects the 389 Directory Server base component, specifically versions prior to 1.3.5.17 and 1.3.6.10. This issue represents a critical security flaw that resides within the LDAP bind request processing mechanism of the directory service. The 389 Directory Server is a comprehensive enterprise directory service that provides authentication, authorization, and directory services for large-scale deployments. The vulnerability manifests when the server processes specially crafted LDAP bind requests, creating a condition where invalid pointer dereference occurs during request handling.
The technical flaw stems from inadequate input validation and memory management within the ns-slapd process that handles LDAP operations. When an LDAP bind request is received, the server performs various validations and processing steps to authenticate users against the directory. However, the vulnerability occurs during this processing phase where the server attempts to access memory locations through pointers that have either been freed or were never properly initialized. This invalid pointer dereference results in a segmentation fault that causes the ns-slapd daemon to terminate abruptly. The flaw is particularly dangerous because it can be triggered by unauthenticated remote attackers, meaning any network-accessible 389-ds server could be targeted without requiring prior authentication credentials.
The operational impact of this vulnerability extends beyond simple service disruption. A successful exploitation results in a denial of service condition that can severely impact enterprise environments relying on directory services for authentication and access control. Organizations using 389-ds for critical infrastructure services such as single sign-on, identity management, and network access control could experience significant operational disruptions. The crash affects the core directory service daemon, potentially causing cascading failures in applications and systems dependent on directory authentication. In large enterprise environments, this could lead to widespread authentication failures, system outages, and potential security implications as services become unavailable. The vulnerability's remote nature means that attackers can exploit it from anywhere on the network, making it particularly dangerous in exposed environments.
Mitigation strategies for CVE-2017-2668 primarily focus on immediate version upgrades to patched releases of the 389-ds-base software. Organizations should prioritize updating to versions 1.3.5.17 or 1.3.6.10, which contain the necessary code fixes to prevent invalid pointer dereference conditions. Additionally, network segmentation and access controls should be implemented to limit exposure of directory services to untrusted networks. The vulnerability aligns with CWE-476, which describes NULL pointer dereference conditions, and can be categorized under ATT&CK technique T1499 for network denial of service attacks. System administrators should also implement monitoring solutions to detect unusual patterns of LDAP bind requests that might indicate exploitation attempts. Regular security assessments and vulnerability scanning should be conducted to identify any remaining unpatched systems within the organization's infrastructure. The fix implemented in the patched versions addresses the root cause by ensuring proper pointer validation and memory management during LDAP bind request processing, preventing the crash condition that previously occurred.