CVE-2024-21597

Junos OS: MX Series: In an AF scenario traffic can bypass configured lo0 firewall filters

State: Published
Severity: 5.3 Medium
Published: Jan 12, 2024
Updated: Jun 3, 2025
Reserved: Dec 27, 2023

Description

An Exposure of Resource to Wrong Sphere vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on MX Series allows an unauthenticated, network-based attacker to bypass the intended access restrictions.

In an Abstracted Fabric (AF) scenario if routing-instances (RI) are configured, specific valid traffic destined to the device can bypass the configured lo0 firewall filters as it's received in the wrong RI context.

This issue affects Juniper Networks Junos OS on MX Series:

* All versions earlier than 20.4R3-S9; * 21.2 versions earlier than 21.2R3-S3; * 21.4 versions earlier than 21.4R3-S5; * 22.1 versions earlier than 22.1R3; * 22.2 versions earlier than 22.2R3; * 22.3 versions earlier than 22.3R2.

Scores

CVSS	Score	Vector	Source
3.1	5.3 Medium	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N	juniper

Weaknesses

CWE-668 Exposure of Resource to Wrong Sphere

Affected Products

Product	Versions
Junos OSJuniper Networks	before 20.4R3-S9Affected 21.2 to before 21.2R3-S3Affected 21.4 to before 21.4R3-S5Affected 22.1 to before 22.1R3Affected 22.2 to before 22.2R3Affected 22.3 to before 22.3R2Affected

References

https://supportportal.juniper.net/JSA75738vendor-advisory
https://www.first.org/cvss/calculator/4.0#CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:Ntechnical-description

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