CVE-2025-21590

MEDIUM 4.4

⚠️ CISA KEV

Junos OS: An local attacker with shell access can execute arbitrary code

CVSS Score

4.4

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-653
Vendor	juniper networks
Product	junos os
Published	Mar 12, 2025
Last Updated	Feb 26, 2026

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CVSS v3 Breakdown

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

Attack Vector

Local

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Unchanged

Confidentiality

None

Integrity

High

Availability

None

Affected Versions

Juniper Networks / Junos OS

0 < 21.2R3-S9 21.4 < 21.4R3-S10 22.2 < 22.2R3-S6 22.4 < 22.4R3-S6 23.2 < 23.2R2-S3 23.4 < 23.4R2-S4 24.2 < 24.2R1-S2, 24.2R2

References

NVD ↗ CVE.org ↗ EPSS Data ↗

supportportal.juniper.net: https://supportportal.juniper.net/JSA93446 cloud.google.com: https://cloud.google.com/blog/topics/threat-intelligence/china-nexus-espionage-targets-juniper-routers cisa.gov: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-21590

Credits

🔍 Juniper SIRT would like to acknowledge and thank Matteo Memelli from Amazon for responsibly reporting this issue. Note: Amazon found the issue during internal security research and not due to exploitation.