Cyber Resilience

CVE-2024-39520

Command Injection in Juniper Junos Os Evolved ≤ 20.4

Command Injection
Published
11 July 2024
Modified
21 November 2024
Patch / advisory
View advisory
CVSS Score v4 8.5
Click a component to see what it means
Raw vectorCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0025 16th percentile
Risk Priority 32 floored blend · peak EPSS

Summary

CVE-2024-39520 is a high-severity OS Command Injection (CWE-78) vulnerability in Juniper Junos Os Evolved. Its CVSS base score is 8.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Command and Scripting Interpreter (T1059); ranked at the 16th 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 Special Elements vulnerability in Juniper Networks Junos OS Evolved commands allows a local, authenticated attacker with low privileges to escalate their privileges to 'root' leading to a full compromise of the system. The Junos OS Evolved…

more

CLI doesn't properly handle command options in some cases, allowing users which execute specific CLI commands with a crafted set of parameters to escalate their privileges to root on shell level. This issue affects Junos OS Evolved: * All version before 20.4R3-S6-EVO, * 21.2-EVO versions before 21.2R3-S4-EVO, * 21.4-EVO versions before 21.4R3-S6-EVO, * 22.2-EVO versions before 22.2R2-S1-EVO, 22.2R3-EVO, * 22.3-EVO versions before 22.3R2-EVO.

CWE(s)
CWE-78

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 →
T1059.003 Windows Command Shell Execution
Adversaries may abuse the Windows command shell for execution.
attack.mitre.org →
T1059.004 Unix Shell Execution
Adversaries may abuse Unix shell commands and scripts for execution.
attack.mitre.org →
T1059.001 PowerShell Execution
Adversaries may abuse PowerShell commands and scripts for execution.
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 →
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2023-28983Same product: Juniper Junos Os Evolved
CVE-2024-39523Same product: Juniper Junos Os Evolved
CVE-2025-60006Same product: Juniper Junos Os Evolved
CVE-2024-39521Same product: Juniper Junos Os Evolved
CVE-2024-39524Same product: Juniper Junos Os Evolved
CVE-2024-39522Same product: Juniper Junos Os Evolved
CVE-2025-52988Same product: Juniper Junos Os Evolved
CVE-2026-33791Same product: Juniper Junos Os Evolved
CVE-2024-47495Same product: Juniper Junos Os Evolved
CVE-2024-21612Same product: Juniper Junos Os Evolved

Affected Assets

juniper
junos os evolved
20.4, 21.2, 21.4, 22.2, 22.3 · ≤ 20.4

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

—

Detect
Catch it (NIST detect / respond)

—

Harden
Shrink the surface (DISA STIG)

—

Validate
Prove the fix (OWASP ASVS)
  • V1.2.5
  • V1.2.8
  • V15.2.5

Mitigating Controls (NIST 800-53 r5) AI

SA-11 Developer Testing and Evaluation good match

Developer testing and evaluation can discover missing or incorrect command sanitization during development.

SI-10 Information Input Validation good match

Input validation directly neutralizes or rejects special characters that would otherwise alter OS command structure.

AC-6 Least Privilege partial match

Least privilege reduces the permissions available to any process that could be subverted by injected commands.

CM-7 Least Functionality partial match

Least functionality restricts available OS commands and interpreters, limiting the blast radius of injection.

SA-8 Security and Privacy Engineering Principles partial match

Secure engineering principles require proper neutralization of untrusted input before command construction.

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

PR.PS-06's SDLC practices directly require secure coding and input handling that blocks command-injection defects, yet the single broad outcome leaves many specific neutralization vectors and verification gaps unaddressed.

PR.PS-02 partial match
prevents

Routine patching/maintenance can remediate known command-injection CVEs in dependencies (partial forward) but does nothing to stop developers from introducing improper neutralization in custom code (none reverse).

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 and code review target insecure use of operating-system command interfaces, catching command-injection flaws introduced during development.

References