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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).

PUBLISHED Reserved 2025-06-23 | Published 2025-07-11 | Updated 2025-07-15 | Assigner juniper




MEDIUM: 5.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

MEDIUM: 6.9CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:N/SI:L/SA:N/AU:Y/R:U/RE:M

Problem types

CWE-693: Protection Mechanism Failure

Product status

Default status
unaffected

Any version before 21.2R3-S9
affected

21.4 (semver) before 21.4R3-S11
affected

22.2 (semver) before 22.2R3-S7
affected

22.4 (semver) before 22.4R3-S7
affected

23.2 (semver) before 23.2R2-S4
affected

23.4 (semver) before 23.4R2-S5
affected

24.2 (semver) before 24.2R2-S1
affected

24.4 (semver) before 24.4R1-S2, 24.4R2
affected

Timeline

2025-07-09:Initial Publication
2025-07-15:Clarified that only traffic destined to the control plane is affected

References

supportportal.juniper.net/JSA100055 vendor-advisory

cve.org (CVE-2025-52951)

nvd.nist.gov (CVE-2025-52951)

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