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Fencer Intel
medium 5.8

CVE-2019-0048 json

EX4300 Series: When a firewall filter is applied to a loopback interface, other firewall filters for multicast traffic may fail

published 7y ago modified 4mo ago also EUVD-2019-0855

cvss
5.8
version 3.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 61%
public exploits
0
none known

Summary

On EX4300 Series switches with TCAM optimization enabled, incoming multicast traffic matches an implicit loopback filter rule first, since it has high priority. This rule is meant for reserved multicast addresses 224.0.0.x, but incorrectly matches on 224.x.x.x. Due to this bug, when a firewall filter is applied on the loopback interface, other firewall filters might stop working for multicast traffic. The command 'show firewall filter' can be used to confirm whether the filter is working. This issue only affects the EX4300 switch. No other products or platforms are affected by this vulnerability. This issue affects: Juniper Networks Junos OS: 14.1X53 versions prior to 14.1X53-D51, 14.1X53-D115 on EX4300 Series; 17.1 versions prior to 17.1R3 on EX4300 Series; 17.2 versions prior to 17.2R3-S2 on EX4300 Series; 17.3 versions prior to 17.3R3-S3 on EX4300 Series; 17.4 versions prior to 17.4R2-S5, 17.4R3 on EX4300 Series; 18.1 versions prior to 18.1R3-S1 on EX4300 Series; 18.2 versions prior to 18.2R2 on EX4300 Series; 18.3 versions prior to 18.3R2 on EX4300 Series.

Patch / fix

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Exploit prediction

0.97% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.0 5.8 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
NVD 3.1 5.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:P/A:N

Affected products

  • Juniper Networks Junos OS

Classification

Weakness
  • CWE-200 Exposure of Sensitive Information to an Unauthorized Actor

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.