Security Resilience

CVE-2024-21599

Juniper Junos 20.4 … 22.1

Published
12 January 2024
Modified
17 June 2026
Patch / advisory
View 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 20th percentile
Risk Priority 49 floored blend · peak EPSS

CVSS and EPSS are reproduced from their sources (NVD, FIRST EPSS). Risk Priority is our own derived reading, not an NVD score.

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 Junk Data (T1001.001); ranked at the 20th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-15 (Development Process, Standards, and Tools) — see the control section below for these in your framework.

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…

more

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)
CWE-401

Related Threats

MITRE ATT&CK Enterprise Techniques

T1001.001 Junk Data Command And Control
Adversaries may add junk data to protocols used for command and control to make detection more difficult.
attack.mitre.org →
T1001.002 Steganography Command And Control
Adversaries may use steganographic techniques to hide command and control traffic to make detection efforts more difficult.
attack.mitre.org →
T1001.003 Protocol or Service Impersonation Command And Control
Adversaries may impersonate legitimate protocols or web service traffic to disguise command and control activity and thwart analysis efforts.
attack.mitre.org →
T1003 OS Credential Dumping Credential Access
Adversaries may attempt to dump credentials to obtain account login and credential material, normally in the form of a hash or a clear text password.
attack.mitre.org →
T1003.001 LSASS Memory Credential Access
Adversaries may attempt to access credential material stored in the process memory of the Local Security Authority Subsystem Service (LSASS).
attack.mitre.org →
T1003.004 LSA Secrets Credential Access
Adversaries with SYSTEM access to a host may attempt to access Local Security Authority (LSA) secrets, which can contain a variety of different credential materials, such as credentials for service accounts.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-22395Same product: Juniper Junos
CVE-2026-33780Same product: Juniper Junos
CVE-2024-21611Same product: Juniper Junos
CVE-2025-21595Same product: Juniper Junos
CVE-2023-22406Same product: Juniper Junos
CVE-2023-28982Same product: Juniper Junos
CVE-2024-39536Same product: Juniper Junos
CVE-2024-21613Same product: Juniper Junos
CVE-2026-21909Same product: Juniper Junos
CVE-2024-39549Same product: Juniper Junos

Affected Assets

juniper
junos
20.4, 21.1, 21.2, 21.3, 21.4

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation (static analysis, fuzzing, or runtime leak detection) directly finds missing deallocation.

SA-15 Development Process, Standards, and Tools partial match

Requiring documented development standards and tools can mandate memory-management disciplines that avoid leaks at introduction.

SA-8 Security and Privacy Engineering Principles partial match

Engineering principles applied during development can require explicit resource-release patterns that stop memory leaks from being coded.

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 partial match
blocks

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.

A.5.14 Information transfer partial match
removes
A.5.15 Access control partial match
removes
A.5.16 Identity management partial match
removes
A.5.17 Authentication information partial match
removes
A.5.18 Access rights partial match
removes
A.8.10 Information deletion partial match
removes

References