CVE-2024-8445 is a vulnerability identified in the 389-ds-base LDAP server software, specifically version 3.1.1. It arises from improper input validation when an authenticated user attempts to modify the userPassword attribute using malformed input. This vulnerability is a follow-up to CVE-2024-2199, where the initial fix did not cover all edge cases, leaving the system susceptible to denial of service (DoS) attacks. An attacker with valid credentials can send specially crafted requests to the LDAP server that cause it to crash, resulting in service unavailability. The vulnerability does not allow unauthorized access or data manipulation beyond causing a crash, thus impacting availability but not confidentiality or integrity. The CVSS v3.1 score is 5.7 (medium severity), reflecting the requirement for authentication (PR:L), no user interaction (UI:N), and local network attack vector (AV:A). No public exploits have been reported yet, but the vulnerability poses a risk to environments relying on 389-ds-base for directory services, especially where userPassword modifications are permitted. The lack of patch links suggests that a fix may be pending or recently released, so organizations should monitor vendor advisories closely.

For European organizations, the primary impact is denial of service on directory services that use 389-ds-base version 3.1.1. LDAP servers are critical for authentication, authorization, and identity management; a crash can disrupt access to multiple dependent applications and services, causing operational downtime and potential business interruptions. Although the vulnerability does not expose sensitive data or allow privilege escalation, the loss of availability can affect sectors such as government, finance, healthcare, and telecommunications, where directory services are foundational. Organizations with large-scale deployments or those that allow authenticated users broad modification rights on userPassword attributes are at higher risk. The medium severity rating indicates that while the threat is not critical, it should not be ignored, especially in environments where uptime and service continuity are essential.

1. Apply vendor patches or updates for 389-ds-base as soon as they become available to address this vulnerability comprehensively. 2. Restrict modification permissions on the userPassword attribute to the minimum necessary set of users or administrators to reduce the attack surface. 3. Implement strict input validation and sanitization controls at the application or middleware level if possible, to detect and block malformed requests before they reach the LDAP server. 4. Monitor LDAP server logs for unusual modification attempts or malformed input patterns that could indicate exploitation attempts. 5. Employ network segmentation and access controls to limit which authenticated users can reach the LDAP server, reducing exposure. 6. Prepare incident response plans to quickly recover from potential denial of service events affecting directory services.