CVE-2024-39517

/// Technical description

An Improper Check for Unusual or Exceptional Conditions vulnerability in the Layer 2 Address Learning Daemon (l2ald) on Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker to cause Denial of Service (DoS).

In an EVPN/VXLAN scenario, when a high amount specific Layer 2 packets are processed by the device, it can cause the Routing Protocol Daemon (rpd) to utilize all CPU resources which causes the device to hang. A manual restart of the rpd is required to restore services.

This issue affects both IPv4 and IPv6 implementations.

This issue affects

Junos OS:

All versions earlier than 21.4R3-S7;

22.1 versions earlier than 22.1R3-S5;

22.2 versions earlier than 22.2R3-S3;

22.3 versions earlier than 22.3R3-S3;

22.4 versions earlier than 22.4R3-S2;

23.2 versions earlier than 23.2R2;

23.4 versions earlier than 23.4R1-S1.

Junos OS Evolved:

All versions earlier than 21.4R3-S7-EVO;

22.1-EVO versions earlier than 22.1R3-S5-EVO;

22.2-EVO versions earlier than

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References