MEDIUM · 5.8

CVE-2025-52951

A Protection Mechanism Failure vulnerability in kernel filter processing of Juniper Networks Junos OS allows an attacker sending IPv6 traffic destined to the device to effectively bypass any firewall ...

Vulnerability Description

A Protection Mechanism Failure vulnerability in kernel filter processing of Juniper Networks Junos OS allows an attacker sending IPv6 traffic destined to the device to effectively bypass any firewall filtering configured on the interface. Due to an issue with Junos OS kernel filter processing, the 'payload-protocol' match is not being supported, causing any term containing it to accept all packets without taking any other action. In essence, these firewall filter terms were being processed as an 'accept' for all traffic on the interface destined for the control plane, even when used in combination with other match criteria. This issue only affects firewall filters protecting the device's control plane. Transit firewall filtering is unaffected by this vulnerability. This issue affects Junos OS:  * all versions before 21.2R3-S9,  * from 21.4 before 21.4R3-S11,  * from 22.2 before 22.2R3-S7,  * from 22.4 before 22.4R3-S7,  * from 23.2 before 23.2R2-S4,  * from 23.4 before 23.4R2-S5,  * from 24.2 before 24.2R2-S1,  * from 24.4 before 24.4R1-S2, 24.4R2. This is a more complete fix for previously published CVE-2024-21607 (JSA75748).

CVSS Score

5.8

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
LOW
Availability
NONE

Affected Products

VendorProductVersions
JuniperJunos< 21.2

Related Weaknesses (CWE)

References

FAQ

What is CVE-2025-52951?

CVE-2025-52951 is a vulnerability with a CVSS score of 5.8 (MEDIUM). A Protection Mechanism Failure vulnerability in kernel filter processing of Juniper Networks Junos OS allows an attacker sending IPv6 traffic destined to the device to effectively bypass any firewall ...

How severe is CVE-2025-52951?

CVE-2025-52951 has been rated MEDIUM with a CVSS base score of 5.8/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2025-52951?

Check the references section above for vendor advisories and patch information. Affected products include: Juniper Junos.