CVE-2025-21590: Juniper Junos OS Improper Isolation or Compartmentalization Vulnerability
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.
Other sources
Juniper Junos OS contains an improper isolation or compartmentalization vulnerability. This vulnerability could allows a local attacker with high privileges to inject arbitrary code.
— CISA
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
Juniper Junos OSto a version that resolves this vulnerability.Fixed in 21.2R3-S9 - Upgrade
Upgrade
Juniper Junos OSto a version that resolves this vulnerability.Fixed in 21.4R3-S10 - Upgrade
Upgrade
Juniper Junos OSto a version that resolves this vulnerability.Fixed in 22.2R3-S6 - Upgrade
Upgrade
Juniper Junos OSto a version that resolves this vulnerability.Fixed in 22.4R3-S6 - Upgrade
Upgrade
Juniper Junos OSto a version that resolves this vulnerability.Fixed in 23.2R2-S3 - Upgrade
Upgrade
Juniper Junos OSto a version that resolves this vulnerability.Fixed in 23.4R2-S4 - Upgrade
Upgrade
Juniper Junos OSto a version that resolves this vulnerability.Fixed in 24.2R1-S2 - Upgrade
Upgrade
Juniper Junos OSto a version that resolves this vulnerability.Fixed in 24.2R2 - Upgrade
Upgrade
Juniper Junos OSto a version that resolves this vulnerability.Fixed in 24.4R1 - Compensating control
If mitigations are unavailable, discontinue use of the product; otherwise apply mitigations per vendor instructions and follow applicable BOD 22-01 guidance for cloud services.
Event History
Frequently Asked Questions
What is the severity of CVE-2025-21590?
CVE-2025-21590 is rated as a high severity vulnerability due to its potential to compromise device integrity through improper isolation.
How do I fix CVE-2025-21590?
To mitigate CVE-2025-21590, it is recommended to update Junos OS to the latest version that addresses this vulnerability.
Who is affected by CVE-2025-21590?
CVE-2025-21590 affects Juniper Networks Junos OS versions up to 24.2R2, including specific versions prior to this.
What type of exploitation is possible with CVE-2025-21590?
CVE-2025-21590 can be exploited by a local attacker with high privileges to inject arbitrary code that compromises the device.
Is CVE-2025-21590 publicly disclosed?
Yes, CVE-2025-21590 has been publicly disclosed, allowing organizations to take necessary precautions and updates.