Junos OS: EX4300-MP Series: IP transit traffic can reach the control plane via loopback interface.

published 2019-04-10 7y ago modified 2026-06-17 4mo ago also EUVD-2019-0848

cvss: 6.5; version 3.0, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.9%; EPSS 0.9% chance of exploitation in 30 days, percentile 59%
public exploits: 0; none known

On EX4300-MP Series devices with any lo0 filters applied, transit network traffic may reach the control plane via loopback interface (lo0). The device may fail to forward such traffic. This issue affects Juniper Networks Junos OS 18.2 versions prior to 18.2R1-S2, 18.2R2 on EX4300-MP Series. This issue does not affect any other EX series devices.

Patch / fix

fixed in 1

Juniper Networks Junos OS 18.2R1-S2, 18.2R2

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Exploit prediction

0.87% chance of exploitation in the next 30 days, higher than 59% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by	version	score	vector
CNA	3.0	6.5	CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L
NVD	3.1	8.6	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
NVD	2.0	5.0	AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

Juniper Networks Junos OS

Classification

Weakness

CWE-284 Improper Access Control

References

kb.juniper.net /JSA10933
mitigation, vendor-advisory

Sources

CVE List CVE-2019-0041
NVD CVE-2019-0041

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