title: Junos OS: QFX5000 Series: Traffic from the network internal to the device (128.0.0.0) may be forwarded to egress interfaces.
description: Juniper Networks Junos OS uses the 128.0.0.0/2 subnet for internal communications between the RE and PFEs. It was discovered that packets utilizing these IP addresses may egress an QFX5000 Series switch, leaking configuration information such as heartbeats, kernel versions, etc. out to the Internet, leading to an information exposure vulnerability. This issue affects Juniper Networks Junos OS on QFX5110, QFX5120, QFX5200, QFX5210 Series, and QFX5100 with QFX 5e Series image installed: All versions prior to 17.3R3-S12; 18.1 versions prior to 18.1R3-S13; 18.3 versions prior to 18.3R3-S5; 19.1 versions prior to 19.1R3-S6; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R2-S6, 19.3R3-S3; 19.4 versions prior to 19.4R1-S4, 19.4R3-S5; 20.1 versions prior to 20.1R2-S2, 20.1R3-S1; 20.2 versions prior to 20.2R3-S2; 20.3 versions prior to 20.3R3-S1; 20.4 versions prior to 20.4R2-S1, 20.4R3; 21.1 versions prior to 21.1R1-S1, 21.1R2;
problem types: CWE-200 Information Exposure
affected:
{
platforms: QFX5000 Series
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 17.3R3-S12, status: affected, version: unspecified, versionType: custom
lessThan: 18.1R3-S13, status: affected, version: 18.1, versionType: custom
lessThan: 18.3R3-S5, status: affected, version: 18.3, versionType: custom
lessThan: 19.1R3-S6, status: affected, version: 19.1, versionType: custom
lessThan: 19.2R1-S7, 19.2R3-S3, status: affected, version: 19.2, versionType: custom
lessThan: 19.3R2-S6, 19.3R3-S3, status: affected, version: 19.3, versionType: custom
lessThan: 19.4R1-S4, 19.4R3-S5, status: affected, version: 19.4, versionType: custom
lessThan: 20.1R2-S2, 20.1R3-S1, status: affected, version: 20.1, versionType: custom
lessThan: 20.2R3-S2, status: affected, version: 20.2, versionType: custom
lessThan: 20.3R3-S1, status: affected, version: 20.3, versionType: custom
lessThan: 20.4R2-S1, 20.4R3, status: affected, version: 20.4, versionType: custom
lessThan: 21.1R1-S1, 21.1R2, status: affected, version: 21.1, versionType: custom
lessThan: 21.2R1, status: affected, version: 21.2, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: NONE
baseScore: 5.3
baseSeverity: MEDIUM
confidentialityImpact: LOW
integrityImpact: NONE
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
version: 3.1
]
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: 17.3R3-S12, 18.1R3-S13, 18.3R3-S5, 19.1R3-S6, 19.2R1-S7, 19.2R3-S3, 19.3R2-S6, 19.3R3-S3, 19.4R1-S4, 19.4R3-S5, 20.1R2-S2, 20.1R3-S1, 20.2R3-S2, 20.3R3-S1, 20.4R2-S1, 20.4R3, 21.1R1-S1, 21.1R2, 21.2R1, and all subsequent releases.
workarounds: Configure a firewall filter to discard packets sourced from the internal network.
Disabling the net.transit_re sysctl flag will also cause management traffic forwarded to the PFE ports to be dropped:
% sysctl -w net.transit_re=0
Note that sysctl flags do not survive a reboot.