Junos
CVE-2021-0252
HIGH
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization Command injection prevention
MITRE ATT&CK
1 technique across 1 tactic: Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 7.8 (HIGH). Attack characteristics: local attack vector, low complexity, low privileges required, no user interaction not required. Public proof-of-concept exploit code is available. |
| Exploit ScenarioDerived | A local attacker with access to the system could inject arbitrary commands into system command execution. |
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Alert meAnalysisAI
NFX Series devices using Juniper Networks Junos OS are susceptible to a local code execution vulnerability thereby allowing an attacker to elevate their privileges via the Junos Device Management. Rated high severity (CVSS 7.8), this vulnerability is low attack complexity. Public exploit code available and no vendor patch available.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Use parameterized APIs, avoid shell execution, validate input with strict allowlists.
Affects your stack
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Technical ContextAI · show details
This vulnerability is classified as Command Injection (CWE-77), which allows attackers to inject arbitrary commands into system command execution. NFX Series devices using Juniper Networks Junos OS are susceptible to a local code execution vulnerability thereby allowing an attacker to elevate their privileges via the Junos Device Management Daemon (JDMD) process.1 version 18.1R1 and later versions prior to 18.2R3-S5; 18.3 versions prior to 18.3R2-S4, 18.3R3-S3; 18.4 versions prior to 18.4R2-S5, 18.4R3-S4; 19.1 versions prior to 19.1R1-S3, 19.1R2; 19.2 versions prior to 19.2R1-S5, 19.2R2. This issue does not affect: Juniper Networks Junos OS versions prior to 18.1R1. This issue does not affect the JDMD as used by Junos Node Slicing such as External Servers use in conjunction with Junos Node Slicing and In-Chassis Junos Node Slicing on MX480, MX960, MX2008, MX2010, MX2020. Affected products include: Juniper Junos. Version information: version 18.1.
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Severity by source
AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
NFX Series devices using Juniper Networks Junos OS are susceptible to a local code execution vulnerability thereby allowing an attacker to elevate their privileges via the Junos Device Management Daemon (JDMD) process. This issue affects Juniper Networks Junos OS on NFX Series: 18.1 version 18.1R1 and later versions prior to 18.2R3-S5; 18.3 versions prior to 18.3R2-S4, 18.3R3-S3; 18.4 versions prior to 18.4R2-S5, 18.4R3-S4; 19.1 versions prior to 19.1R1-S3, 19.1R2; 19.2 versions prior to 19.2R1-S5, 19.2R2. This issue does not affect: Juniper Networks Junos OS versions prior to 18.1R1. This issue does not affect the JDMD as used by Junos Node Slicing such as External Servers use in conjunction with Junos Node Slicing and In-Chassis Junos Node Slicing on MX480, MX960, MX2008, MX2010, MX2020.
Threat Intelligence Overview
NVD
CVE.org
EPSS
GitHub
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
OS command injection occurs when an application passes unsanitized user input directly into system shell commands.
Remote Code Execution represents the critical moment when an attacker successfully runs arbitrary code on a target system without physical access.
Affected Products (CPE)NVD
named in ISC BIND 9.x before 9.9.8-P4 and 9.10.x before 9.10.3-P4 does not properly handle DNAME records when parsing fe
named in ISC BIND 9.x before 9.9.8-P4 and 9.10.x before 9.10.3-P4 allows remote attackers to cause a denial of service (
A security vulnerability in An Improper (CVSS 6.7) that allows a local attacker with high privileges. Risk factors: acti
A PHP External Variable Modification vulnerability in J-Web of Juniper Networks Junos OS on EX Series and SRX Series all
jsdm/ajax/port.php in J-Web in Juniper Junos before 10.4R13, 11.4 before 11.4R7, 12.1 before 12.1R5, 12.2 before 12.2R3,
Juniper Junos 11.4 before R11, 12.1 before R9, 12.1X44 before D30, 12.1X45 before D20, 12.1X46 before D15, 12.1X47 befor
NFX Series devices using Juniper Networks Junos OS are susceptible to a local command execution vulnerability thereby al
Insufficient validation of environment variables in the telnet client supplied in Junos OS can lead to stack-based buffe
An Out-of-Bounds Write vulnerability in the H.323 ALG of Juniper Networks Junos OS allows an unauthenticated, network-ba
On QFX10000 Series devices using Juniper Networks Junos OS when configured as transit IP/MPLS penultimate hop popping (P
A Missing Release of Memory after Effective Lifetime vulnerability in the kernel of Juniper Networks Junos OS allows an
An Uncontrolled Memory Allocation vulnerability leading to a Heap-based Buffer Overflow in the packet forwarding engine
Exploit-DB