Junos OS: NFX Series: Local Command Execution Vulnerability in JDMD Leads to Privilege Escalation
NFX Series devices using Juniper Networks Junos OS are susceptible to a local command 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 17.2 version 17.2R1 and later versions prior to 18.3R3-S4; 18.4 versions prior to 18.4R2-S5, 18.4R3-S5; 19.1 versions prior to 19.1R1-S3; 19.2 version 19.1R2 and later versions prior to 19.2R3; 19.3 versions prior to 19.3R3; 19.4 versions prior to 19.4R2-S2. 19.4 versions 19.4R3 and above. This issue does not affect Juniper Networks Junos OS versions prior to 17.2R1. 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.
- Published
- Apr 22, 2021
- Updated
- Jun 16, 2026
- EPSS
- 0.5% · 44th percentile
- CWE
- CWE-77
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Report tools
Action score
31
Monitor
Low priority for now.
- CVSS
- 31 / 40 · 7.8 / 10
- CISA KEV
- 0 / 30 · Not listed
- EPSS
- 0 / 30 · 0.5%
CNA vs NVD score
- NVD
- 7.8
- CNA · juniper
- 7.8
- agree
The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.
Affected systems
| Vendor | Product | CPE |
|---|---|---|
| juniper | junos | cpe:2.3:o:juniper:junos |
| juniper | nfx150 | cpe:2.3:h:juniper:nfx150 |
| juniper | nfx250 | cpe:2.3:h:juniper:nfx250 |
| juniper | nfx350 | cpe:2.3:h:juniper:nfx350 |
Affected versions
NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.
- juniper junos17.2
- juniper junos17.3
- juniper junos17.4
- juniper junos18.1
- juniper junos18.2
- juniper junos18.3
- juniper junos18.4
- juniper junos19.1
- juniper junos19.2
- juniper junos19.3
- juniper junos19.4
Versions reported by the vendor
Affected version ranges reported by the assigning authority (juniper). Independent of NVD's CPE analysis and usually ahead of it.
Juniper Networks Junos OS
- unspecified and later · before 18.3R3-S4affected
- 17.2R1 and later · before 17.2*affected
- 18.4 and later · before 18.4R2-S5, 18.4R3-S5affected
- 19.1 and later · before 19.1R1-S3affected
- 19.1R2 and later · before 19.2*affectedfixed in 19.2R3
- 19.3 and later · before 19.3R3affected
- 19.4 and later · before 19.4R2-S2affected
- unspecified and later · before 17.2R1not affected
Same product
juniper: all recordsOther highest-scoring records for the same primary product.
- CVE-2023-36845Junos OS: EX and SRX Series: A PHP vulnerability in J-Web allows an unauthenticated to control an important environment variableKEV98Now
- CVE-2023-36846Junos OS: SRX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload arbitrary filesKEV79This week
- CVE-2023-36844Junos OS: EX Series: A PHP vulnerability in J-Web allows an unauthenticated attacker to control important environment variablesKEV78This week
- CVE-2023-36847Junos OS: EX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload arbitrary filesKEV76This week
- CVE-2020-1631Out of Cycle Security Advisory: Junos OS: Security vulnerability in J-Web and web based (HTTP/HTTPS) servicesKEV70This week
- CVE-2025-21590Junos OS: An local attacker with shell access can execute arbitrary codeKEV57Plan
Remediation
Which version to upgrade to
Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.
| Product / package | Fixed version | Source |
|---|---|---|
| Juniper Networks Junos OS | 19.2R3 | Vendor (CNA) |
Exploit status
No known public exploit
No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.
Research context
For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.
Timeline
From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.
No dated events beyond publication.
FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).
Patch and commit links
Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.
No commit or PR link among the references.
Credits
All researchersFinders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.
- Cyrille CHATRASOrange group
Variant candidates
Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.
—
Chain candidates
An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.
- CVE-2021-02680 days apartJunos OS: J-Web has an Improper Neutralization of CRLF Sequences in its HTTP Headers which allows an attacker to carry out multiple types of attacks.37Monitor
- CVE-2021-02600 days apartJunos OS: SNMP fails to properly perform authorization checks on incoming received SNMP requests.29Monitor
Bug bounty scope
No known public program.
Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).
Technical details
Attack conditions
- Someone with local access to the system can trigger it.
- A low-privileged account is enough.
- No user action is required.
- No special conditions are required; it is repeatable.
If successful
- Confidentiality
- high · data can be read
- Integrity
- high · data or configuration can be modified
- Availability
- high · the service can be disrupted
- Attack vector
- Local
- Attack complexity
- Low
- Privileges required
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality impact
- High
- Integrity impact
- High
- Availability impact
- High
Weakness class (CWE)
CWE-77 · Improper Neutralization of Special Elements used in a Command ('Command Injection')CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
nvd-primary
Attack context
MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.
Attack patterns (CAPEC)
- LDAP InjectionCAPEC-136likelihood: High · High
- Command DelimitersCAPEC-15likelihood: High · High
- IMAP/SMTP Command InjectionCAPEC-183Medium
- Command InjectionCAPEC-248likelihood: Medium · High
- Manipulating Writeable Terminal DevicesCAPEC-40likelihood: High · Very High
- Exploiting Multiple Input Interpretation LayersCAPEC-43likelihood: Medium · High
- Manipulating Writeable Configuration FilesCAPEC-75likelihood: High · Very High
- Manipulating Web Input to File System CallsCAPEC-76likelihood: High · Very High
ATT&CK techniques
—
Noroxi analysis
No Noroxi analysis for this record yet
We don't hand-write analysis for all 385,000+ vulnerabilities; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.
We use this product, ask for helpChange log
- Fix✗ → ✓
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References
Vendor advisories and official records. Exploit/PoC links are deliberately left out.