CVE-2019-0048

MEDIUM

Juniper Junos OS on EX4300 Series - Firewall Filter Bypass via Multicast Traffic Mismatch

Title source: llm
STIX 2.1

Description

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.

References (1)

Core 1
Core References
Patch, Vendor Advisory x_refsource_confirm
https://kb.juniper.net/JSA10942

Scores

CVSS v3 5.8
EPSS 0.0021
EPSS Percentile 43.0%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

Details

CWE
CWE-200
Status published
Products (6)
juniper/junos 14.1x53 (13 CPE variants)
juniper/junos 17.1 (10 CPE variants)
juniper/junos 17.2 (9 CPE variants)
juniper/junos 17.3 (7 CPE variants)
juniper/junos 17.4 (10 CPE variants)
juniper/junos 18.1
Published Jul 11, 2019
Tracked Since Feb 18, 2026