# CVE-2025-21590: Juniper Junos OS Improper Isolation or Compartmentalization Vulnerability

- Exploited (CISA KEV): yes, added 2025-03-13
- Published: 2025-03-12
- CVSS: 6.7 MEDIUM (v4.0)
- EPSS: 1.7% (78th percentile)
- CWE: CWE-653

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.

## Edge WAF coverage (claimed by vendors, not measured)

| Vendor | Status | First rule | Days after publication |
|---|---|---|---|
| Cloudflare | No public claim | — | — |
| AWS | No public claim | — | — |
| Microsoft Azure | No public claim | — | — |
| Google Cloud | No public claim | — | — |
| Fastly | Before feed history | — | — |
| F5 | No public claim | — | — |
| Akamai | No public source | — | — |
| OWASP CRS | No public claim | — | — |

"No public claim" means no vendor statement names this CVE; "Before feed history" means the CVE is older than the vendor feed. In both cases generic rules may still block it.

HTML: https://cve.vigilbase.com/cve/CVE-2025-21590 · JSON: https://cve.vigilbase.com/api/v1/cves/CVE-2025-21590