March 13, 2025 · Applied Cybernetics Group
CVE-2025-21590 — Juniper Junos OS
Juniper Junos OS Improper Isolation or Compartmentalization Vulnerability
- Added to KEV
2025-03-13- Federal due date
2025-04-03- Vendor
- Juniper
- Product
- Junos OS
- EPSS
- 76.6th percentile (score 0.017, as of
2026-10-04) - NVD CVSS v3.1
- 4.4 (MEDIUM)
- Ransomware use
- Unknown
- ATT&CK
- T1059 , T1068 · signal rollup
- Upstream
- https://nvd.nist.gov/vuln/detail/CVE-2025-21590
CISA short description
Juniper Junos OS contains an improper isolation or compartmentalization vulnerability. This vulnerability could allows a local attacker with high privileges to inject arbitrary code.
Required action
Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
NVD 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.