OpenLDAP Improper Access Control List Protections Security Bypass Vulnerability [CVE-2019-13565]

CVE number – CVE-2019-13565

A vulnerability in OpenLDAP could allow an authenticated, remote attacker to bypass security restrictions on a targeted system. The vulnerability exists because the affected software does not properly impose access control list (ACL) protections while using Simple Authentication and Security Layer (SASL) authentication and session encryption. An attacker could exploit this vulnerability by making an SASL bind for any identity within the ACL. A successful exploit could allow the attacker to bypass security restrictions on the targeted system.Proof-of-concept (PoC) code that demonstrates an exploit of this vulnerability is publicly available. OpenLDAP has confirmed the vulnerability and released a software update.

Analysis

• To exploit this vulnerability, the attacker must have user-level access to the targeted system. This access requirement may reduce the likelihood of a successful exploit.

Safeguards

• Administrators are advised to apply the appropriate updates.Administrators are advised to allow only trusted users to have network access.Administrators are advised to run both firewall and antivirus applications to minimize the potential of inbound and outbound threats.Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.Administrators can help protect affected systems from external attacks by using a solid firewall strategy.Administrators are advised to monitor affected systems.

Vendor Announcements

• OpenLDAP has released a security advisory at the following link: ACL protections get lost if same identity uses different SSF levels

Fixed Software

• OpenLDAP has released a software update at the following link: OpenLDAP 2.4.48