Cyber Resilience

CVE-2024-21599

Juniper Junos 20.4 … 22.1

Published
12 January 2024
Modified
17 June 2026
Patch / advisory
CVSS Score v3.1 6.5
Click a component to see what it means
Raw vectorCVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS Score 0.0029 21th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2024-21599 is a medium-severity Missing Release of Memory after Effective Lifetime (CWE-401) vulnerability in Juniper Junos. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Network Denial of Service (T1498); ranked at the 21th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability Data

A Missing Release of Memory after Effective Lifetime vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on MX Series allows an adjacent, unauthenticated attacker to cause a Denial of Service (DoS). If an MX Series device…

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receives PTP packets on an MPC3E that doesn't support PTP this causes a memory leak which will result in unpredictable behavior and ultimately in an MPC crash and restart. To monitor for this issue, please use the following FPC vty level commands: show heap shows an increase in "LAN buffer" utilization and show clksync ptp nbr-upd-info shows non-zero "Pending PFEs" counter. This issue affects Juniper Networks Junos OS on MX Series with MPC3E: * All versions earlier than 20.4R3-S3; * 21.1 versions earlier than 21.1R3-S4; * 21.2 versions earlier than 21.2R3; * 21.3 versions earlier than 21.3R2-S1, 21.3R3; * 21.4 versions earlier than 21.4R2; * 22.1 versions earlier than 22.1R2.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise TechniquesAI

T1498 Network Denial of Service Impact
Adversaries may perform Network Denial of Service (DoS) attacks to degrade or block the availability of targeted resources to users.
Why these techniques?

The vulnerability enables a Network Denial of Service (T1498) by allowing an adjacent unauthenticated attacker to trigger a memory leak in the Packet Forwarding Engine via PTP packets, leading to MPC crash and restart.

CVEs Like This One

CVE-2023-22395Same product: Juniper Junos
CVE-2024-21600Same product: Juniper Junos
CVE-2024-47494Same product: Juniper Junos
CVE-2026-21916Same product: Juniper Junos
CVE-2025-21601Same product: Juniper Junos
CVE-2025-52986Same product: Juniper Junos
CVE-2024-39536Same product: Juniper Junos
CVE-2023-36843Same product: Juniper Junos
CVE-2026-21903Same product: Juniper Junos
CVE-2025-52951Same product: Juniper Junos

Affected Assets

juniper
junos
20.4, 21.1, 21.2, 21.3, 21.4

Mitigating Controls

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure SDLC practices directly enforce proper memory allocation/deallocation via coding standards, reviews, and tooling.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

detects

Security testing in development can detect unreleased memory, providing partial coverage of the weakness.

prevents

Secure development life cycle mandates memory-management practices that reduce missing-release defects.

prevents

Application security requirements can specify explicit memory-release rules, partially mitigating the weakness.

prevents

Secure system architecture and engineering principles include resource-management guidelines that address memory leaks.

prevents

Secure coding standards directly require proper allocation/deallocation, covering most of this weakness.

detects

Capacity management may detect memory exhaustion symptoms but does not prevent the coding flaw.

References