Cyber Resilience

CVE-2024-21600

Juniper Junos 20.4 … 22.2

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 0.0032 25th percentile
Risk Priority 49 floored blend · peak EPSS

Summary

CVE-2024-21600 is a medium-severity Improper Neutralization of Equivalent Special Elements (CWE-76) vulnerability in Juniper Junos. Its CVSS base score is 6.5 (Medium).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked at the 25th 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 SI-10 (Information Input Validation) — see the control section below for these in your framework.

OWASP Top 10 for Web (2025)

A05:2025 Injection

EU & UK References

Vulnerability Data

An Improper Neutralization of Equivalent Special Elements vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on PTX Series allows a unauthenticated, adjacent attacker to cause a Denial of Service (DoS). When MPLS packets are meant to…

more

be sent to a flexible tunnel interface (FTI) and if the FTI tunnel is down, these will hit the reject NH, due to which the packets get sent to the CPU and cause a host path wedge condition. This will cause the FPC to hang and requires a manual restart to recover. Please note that this issue specifically affects PTX1000, PTX3000, PTX5000 with FPC3, PTX10002-60C, and PTX10008/16 with LC110x. Other PTX Series devices and Line Cards (LC) are not affected. The following log message can be seen when the issue occurs: Cmerror Op Set: Host Loopback: HOST LOOPBACK WEDGE DETECTED IN PATH ID <id> (URI: /fpc/<fpc>/pfe/<pfe>/cm/<cm>/Host_Loopback/<cm>/HOST_LOOPBACK_MAKE_CMERROR_ID[<id>]) This issue affects Juniper Networks Junos OS: * All versions earlier than 20.4R3-S8; * 21.1 versions earlier than 21.1R3-S4; * 21.2 versions earlier than 21.2R3-S6; * 21.3 versions earlier than 21.3R3-S3; * 21.4 versions earlier than 21.4R3-S5; * 22.1 versions earlier than 22.1R2-S2, 22.1R3; * 22.2 versions earlier than 22.2R2-S1, 22.2R3.

CWE(s)
CWE-76NVD-CWE-Other

Related Threats

MITRE ATT&CK Enterprise Techniques

T1059 Command and Scripting Interpreter Execution
Adversaries may abuse command and script interpreters to execute commands, scripts, or binaries.
attack.mitre.org →
T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
attack.mitre.org →
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
attack.mitre.org →
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
attack.mitre.org →
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
attack.mitre.org →
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
attack.mitre.org →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-22399Same product: Juniper Junos
CVE-2025-21591Same product: Juniper Junos
CVE-2026-21903Same product: Juniper Junos
CVE-2024-21594Same product: Juniper Junos
CVE-2024-21591Same product: Juniper Junos
CVE-2024-39511Same product: Juniper Junos
CVE-2023-36842Same product: Juniper Junos
CVE-2025-30657Same product: Juniper Junos
CVE-2024-21601Same product: Juniper Junos
CVE-2024-21616Same 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

SA-11 requires developer testing and evaluation that can discover failures to neutralize equivalent special elements.

SI-10 Information Input Validation good match

SI-10 requires validation of information inputs, directly stopping incomplete neutralization of equivalent special elements.

SA-8 Security and Privacy Engineering Principles partial match

SA-8 mandates security engineering principles such as complete input validation and sanitization that cover equivalent special-element forms.

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 require consistent neutralization of all equivalent special elements during input validation and sanitization.

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.8.29 Security testing in development and acceptance mostly match
finds

Security testing can detect incomplete neutralization but does not prevent the weakness itself.

A.8.25 Secure development life cycle partial match
prevents

Secure development life cycle mandates input validation and neutralization of all equivalent special elements.

A.8.26 Application security requirements partial match
prevents

Application security requirements include rules for handling special characters and equivalent encodings.

A.8.27 Secure system architecture and engineering principles partial match
prevents

Secure system architecture principles require consistent canonicalization and neutralization of equivalent inputs.

A.8.28 Secure coding partial match
prevents

Secure coding standards directly address proper neutralization of all equivalent special elements.

References