CVE intelligence and bounded remediation

CVE-2024-30386 — Juniper Junos security vulnerability

High CVSS 7.1

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.

Severity
High
CVSS
7.1 (4.0)
Published
2024-04-12
CISA KEV
Not currently listed
Ecosystem
operating-system
Weaknesses
CWE-416

Affected products

  • juniper / junos
  • juniper / junos / 20.4

Showing 2 representative product identities from 160 source matches. Confirm exact affected versions with the linked vendor and NVD evidence.

Matched remediation archetype

Use-after-free, double free, and expired resource use

This catalog composition supplies bounded fallback guidance. Explicitly reviewed curated workflows load with the complete record below.

Check exposure

  • Trace ownership, references, callbacks, asynchronous tasks, and teardown paths around the affected object or resource.
  • Identify reachable inputs and timing or state transitions that can release the object while references remain.
  • Confirm affected builds, allocators, feature flags, architectures, and process privileges.

Remediate safely

  • Apply the maintained ownership or lifetime fix and rebuild all artifacts containing the affected native code.
  • Use explicit ownership, safe reference management, cancellation and join semantics, and idempotent teardown.
  • Add deterministic lifetime tests plus isolated sanitizer and concurrency coverage for shutdown and error paths.

Authoritative sources

Complete CVE record and remediation plan

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