CVE-2025-52951

Junos OS: IPv6 firewall filter fails to match payload-protocol

State
Published
Severity
6.9 Medium
Published
Jul 11, 2025
Updated
Jul 15, 2025
Reserved
Jun 23, 2025

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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).

Scores

CVSSScoreVectorSource
4.06.9 MediumCVSS: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:Mjuniper
3.15.8 MediumCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:Njuniper

Weaknesses

  • CWE-693 Protection Mechanism Failure

Affected Products

ProductVersions
Junos OSJuniper Networks
  • before 21.2R3-S9Affected
  • 21.4 to before 21.4R3-S11Affected
  • 22.2 to before 22.2R3-S7Affected
  • 22.4 to before 22.4R3-S7Affected
  • 23.2 to before 23.2R2-S4Affected
  • 23.4 to before 23.4R2-S5Affected
  • 24.2 to before 24.2R2-S1Affected
  • 24.4 to before 24.4R1-S2, 24.4R2Affected

References

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