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NVD / CVE Program· CNA juniper

CVE-2025-21590: Junos OS: An local attacker with shell access can execute arbitrary code

MediumCVSS 6.7 · v4.0KEVWeaponized Fix available

Noroxi assessment

Priority: Plan (action score 57/100)

  • CISA has confirmed exploitation in the wild (Mar 13, 2025). Remediation deadline for US federal agencies: Apr 3, 2025.
  • Probability of exploitation in the next 30 days: 1.7% (FIRST EPSS); higher than 78.1% of all records.
  • Someone with local access to the system can trigger it. Administrator privileges are required. No user action is required. No special conditions are required; it is repeatable.
  • Fixed version: Juniper Networks Junos OS 21.2R3-S9, 21.4R3-S10, 22.2R3-S6.
  • Severity is disputed: the assigning authority (CNA) scores it 4.4, NVD 6.7.

Add it to your regular patch cycle. Upgrade to Juniper Networks Junos OS 21.2R3-S9, 21.4R3-S10, 22.2R3-S6 or later.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

Primary sources: NVD · CVE.org · CISA KEV · FIRST EPSS

An Improper Isolation or Compartmentalization vulnerability in the kernel of Juniper Networks Junos OS allows a local attacker with high privileges to compromise the integrity of the device. A local attacker with access to the shell is able to inject arbitrary code which can compromise an affected device. This issue is not exploitable from the Junos CLI. This issue affects Junos OS:  * All versions before 21.2R3-S9, * 21.4 versions before 21.4R3-S10,  * 22.2 versions before 22.2R3-S6,  * 22.4 versions before 22.4R3-S6,  * 23.2 versions before 23.2R2-S3,  * 23.4 versions before 23.4R2-S4, * 24.2 versions before 24.2R1-S2, 24.2R2.

Published
Mar 12, 2025
Updated
Oct 1, 2026
EPSS
1.7% · 78th percentile

Report tools

JSON

Action score

57

Plan

Add it to your regular patch cycle.

CVSS
26 / 40 · 6.7 / 10
CISA KEV
30 / 30 · Listed
EPSS
1 / 30 · 1.7%

CISA SSVC decision

Exploitation
active
Automatable
no
Technical impact
total

Vulnrichment: CISA's decision-tree inputs.

CNA vs NVD score

NVD
—
CNA · juniper
4.4
NVD has not scored this yet; the score shown is the CNA’s.

CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Actively exploited in the wild

CISA added this to its Known Exploited Vulnerabilities catalog on Mar 13, 2025. That signals real attacks, not theory.

Remediation deadline for US federal agencies: Apr 3, 2025.

Get told when this record changes

  • In CISA KEV: exploitation in the wild confirmed
  • Weaponized exploit exists
  • A fix has been released

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2025-21590

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

VendorProduct
juniperjunos

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

    • before 21.2R3-S9affected · semver
    • 21.4 and later · before 21.4R3-S10affected · semver
    • 22.2 and later · before 22.2R3-S6affected · semver
    • 22.4 and later · before 22.4R3-S6affected · semver
    • 23.2 and later · before 23.2R2-S3affected · semver
    • 23.4 and later · before 23.4R2-S4affected · semver
    • 24.2 and later · before 24.2R1-S2, 24.2R2affected · semver
Affected versions · NVD (8)

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • juniper junosbefore 21.2
  • juniper junos21.2
  • juniper junos21.4
  • juniper junos22.2
  • juniper junos22.4
  • juniper junos23.2
  • juniper junos23.4
  • juniper junos24.2

Same product

juniper: all records

Other 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 variableKEV
    98Now
  • CVE-2023-36846Junos OS: SRX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload arbitrary filesKEV
    79This week
  • CVE-2023-36844Junos OS: EX Series: A PHP vulnerability in J-Web allows an unauthenticated attacker to control important environment variablesKEV
    78This week

Published before and after this one in the same product

  • ← EarlierCVE-2025-21598Jan 9, 2025 · Junos OS and Junos OS Evolved: When BGP traceoptions are configured, receipt of malformed BGP packets causes RPD to crash
    32Monitor
  • ← EarlierCVE-2024-39564Feb 5, 2025 · Junos OS and Junos OS Evolved: Receipt of malformed BGP path attributes leads to RPD crash
    34Monitor
  • Later →CVE-2025-21591Apr 9, 2025 · Junos OS: An unauthenticated adjacent attacker sending a malformed DHCP packet causes jdhcpd to crash
    28Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
Juniper Networks Junos OS21.2R3-S9Vendor (CNA)
Juniper Networks Junos OS21.4R3-S10Vendor (CNA)
Juniper Networks Junos OS22.2R3-S6Vendor (CNA)
Juniper Networks Junos OS22.4R3-S6Vendor (CNA)
Juniper Networks Junos OS23.2R2-S3Vendor (CNA)
Juniper Networks Junos OS23.4R2-S4Vendor (CNA)
Juniper Networks Junos OS24.2R1-S2, 24.2R2Vendor (CNA)

Exploit status

Weaponized

A ready exploit tool or active in-the-wild use is known for this vulnerability. This should be your top priority.

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.

  1. Published
  2. CISA KEVsame day
  3. TodayNov 12, 2026+610 d

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

  • CVE-2024-30388334 days apartJunos OS: QFX5000 Series and EX Series: Specific malformed LACP packets will cause flaps
    28Monitor

Not on record for this CVE: EPSS history · patch commit or PR link · public bounty program.

Technical details

Attack conditions

  • Someone with local access to the system can trigger it.
  • Administrator privileges are required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
Integrity
Availability
Attack vector
Local
Attack complexity
Low
Privileges required
High
User interaction
None
Scope
X

Weakness class (CWE)

CWE-653 · Improper Isolation or Compartmentalization

CVSS vector

CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/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

nvd-secondary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

MITRE has no CAPEC/ATT&CK mapping for this CWE.

References

Show all references (2 more)

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records