CVE-2019-0048

high-risk
Published 2019-07-11

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.

Do I need to act?

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0.21% chance of exploitation
EPSS score — low exploit probability
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Not on CISA KEV list
No confirmed active exploitation reported to CISA
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Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
5
CVSS 5.8/10 Medium
NETWORK / LOW complexity

Affected Vendors

51
/ 100
high-risk
Severity 22/34 · High
Exploitability 1/34 · Minimal
Exposure 28/34 · Critical