CVE-2024-30386: Juniper Junos

Medium severity, CVSS 5.3. EPSS: 0.3% chance of exploitation in the next 30 days.

A Use-After-Free vulnerability in the Layer 2 Address Learning Daemon (l2ald) of Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker to cause l2ald to crash leading to a Denial-of-Service (DoS). In an EVPN-VXLAN scenario, when state updates are received and processed by the affected system, the correct order of some processing steps is not ensured, which can lead to an l2ald crash and restart. Whether the crash occurs depends on system internal timing which is outside the attackers control. This issue affects: Junos OS:  * All versions before 20.4R3-S8, * 21.2 versions before 21.2R3-S6, * 21.3 versions before 21.3R3-S5, * 21.4 versions before 21.4R3-S4, * 22.1 versions before 22.1R3-S3, * 22.2 versions before 22.2R3-S1, * 22.3 versions before 22.3R3,, * 22.4 versions before 22.4R2; Junos OS Evolved:  * All versions before 20.4R3-S8-EVO, * 21.2-EVO versions before 21.2R3-S6-EVO,  * 21.3-EVO versions before 21.3R3-S5-EVO, * 21.4-EVO versions before 21.4R3-S4-EVO, * 22.1-EVO versions before 22.1R3-S3-EVO, * 22.2-EVO versions before 22.2R3-S1-EVO, * 22.3-EVO versions before 22.3R3-EVO, * 22.4-EVO versions before 22.4R2-EVO.

Affected products

• Juniper Junos: before 20.4 (fixed in 20.4); version 20.4 only; version 21.2 only; version 21.3 only; version 21.4 only; version 22.1 only; …
• Juniper Junos OS Evolved: before 20.4 (fixed in 20.4); version 20.4 only; version 21.2 only; version 21.3 only; version 21.4 only; version 22.1 only; …

Published 2024-04-12. Last modified 2026-06-17.