CVE-2025-21590
Junos OS: An local attacker with shell access can execute arbitrary code
- Medium 6.7
- Exploited: added to CISA KEV 13 Mar 2025
Description
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.
Key facts
- Published
- 12 Mar 2025
- Last changed
- 26 Feb 2026
- Assigned by
- juniper
- KEV added
- 13 Mar 2025
- KEV fix due
- 3 Apr 2025
- EPSS
- 1.749% likely to be exploited in the next 30 days, higher than 78.223% of CVEs (scores for 15 Nov 2026)
- SSVC (CISA)
- Exploitation: active; Automatable: no; Technical impact: total
Severity scores
Each score is shown as its source gave it. They are not averaged or merged.
- 4.4CVSS 3.1, Mediumfrom the CNA (juniper)
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:H/A:N - 6.7CVSS 4.0, Mediumfrom the CNA (juniper)
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
What to do
- The following software releases have been updated to resolve this specific issue: 21.2R3-S9, 21.4R3-S10, 22.2R3-S6, 22.4R3-S6, 23.2R2-S3, 23.4R2-S4, 24.2R1-S2, 24.2R2, 24.4R1, and all subsequent releases. Please note that this issue is not fixed for all platforms in the releases specified in the solution section. For the following products the fix is only available in these releases: SRX300 Series 21.2R3-S9, 23.4R2-S5*, 24.4R1 SRX550HM 22.2R3-S7* EX4300 Series 21.4R3-S11* (except EX4300-48MP which has fixes available as indicated in the solution) EX4600 21.4R3-S11* (except EX4650 which has fixes available as indicated in the solution) ACX1000, ACX1100, ACX2100, ACX2200, ACX4000, ACX500 21.2R3-S9 MX104 21.2R3-S9 * Future ReleaseCNA solution statement
- It is strongly recommended to mitigate the risk of exploitation by restricting shell access to trusted users only.CNA workaround statement
- Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.CISA KEV required action
Historical context and remediation
This reference retains the original CVE publication date. A recent record update does not mean a new attack occurred.
No separately sourced impact summary is available on this page yet. Consult the description, version data and dated exploitation evidence.
Version statuses below come from the CNA. An “unaffected” version is not necessarily a currently supported release or proof of a patch date. EPSS is a dated risk estimate, not a count of historical attacks.
Affected products
| Vendor | Product | Versions |
|---|---|---|
| Juniper Networks | Junos OS |
|
Timeline
- 12 Mar 2025 Published
- 12 Mar 2025 Initial Publication
- 12 Mar 2025 Corrected hotlinks for CVSS assessments
- 13 Mar 2025 CVE-2025-21590 added to CISA KEV
- 13 Mar 2025 Added to the CISA KEV catalogue
- 14 Mar 2025 Rephrased sentences on Amazon involvement to reduce the chance for confusion
- 9 Apr 2025 Updated solution section to clarify which platforms are not fixed in all but only in specific releases
- 14 Apr 2025 For the products/platforms specifically mentioned in the solution section: Please note that Junos OS version 21.2R3-S9.20, which was made available last week, does not address the issue completely. We'll publish an updated version with the complete fix and update this advisory as soon as possible.
- 6 May 2025 For the products/platforms specifically mentioned in the solution section: Please note that Junos OS version 21.2R3-S9.21 has been publish with the complete fix.