title: EX4300 Series: When a firewall filter is applied to a loopback interface, other firewall filters for multicast traffic may fail
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.
problem types: CWE-200 Information Exposure
affected:
{
product: Junos OS
vendor: Juniper Networks
versions:
status: affected, version: 14.1X53 versions prior to 14.1X53-D51 and 14.1X53-D115 on EX4300 Series
status: affected, version: 17.1 versions prior to 17.1R3 on EX4300 Series
status: affected, version: 17.2 versions prior to 17.2R3-S2 on EX4300 Series
status: affected, version: 17.3 versions prior to 17.3R3-S3 on EX4300 Series
status: affected, version: 17.4 versions prior to 17.4R2-S5 and 17.4R3 on EX4300 Series
status: affected, version: 18.1 versions prior to 18.1R3-S1 on EX4300 Series
status: affected, version: 18.2 versions prior to 18.2R2 on EX4300 Series
status: affected, version: 18.3 versions prior to 18.3R2 on EX4300 Series
}
metrics:
cvssV3_0: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: NONE
baseScore: 5.8
baseSeverity: MEDIUM
confidentialityImpact: NONE
integrityImpact: LOW
privilegesRequired: NONE
scope: CHANGED
userInteraction: NONE
vectorString: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N
version: 3.0
]
exploits: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.
solutions: The following software releases have been updated to resolve this specific issue: 14.1X53-D51, 14.1X53-D115, 17.1R3, 17.2R3-S2, 17.3R3-S3, 17.4R2-S5, 17.4R3, 18.1R3-S1, 18.2R2, 18.3R2, 18.4R1, and all subsequent releases.
workarounds: Disabling TCAM optimization will mitigate this issue.