title: Junos: SRX cluster denial of service vulnerability in flowd due to multicast packets
description: When Express Path (formerly known as service offloading) is configured on Juniper Networks SRX1400, SRX3400, SRX3600, SRX5400, SRX5600, SRX5800 in high availability cluster configuration mode, certain multicast packets might cause the flowd process to crash, halting or interrupting traffic from flowing through the device and triggering RG1+ (data-plane) fail-over to the secondary node. Repeated crashes of the flowd process may constitute an extended denial of service condition. This service is not enabled by default and is only supported in high-end SRX platforms. Affected releases are Juniper Networks Junos OS 12.3X48 prior to 12.3X48-D45, 15.1X49 prior to 15.1X49-D80 on SRX1400, SRX3400, SRX3600, SRX5400, SRX5600, SRX5800.
problem types: denial of service
affected:
{
platforms: SRX1400, SRX3400, SRX3600, SRX5400, SRX5600, SRX5800
product: Junos OS
vendor: Juniper Networks
versions:
status: affected, version: 12.3X48 prior to 12.3X48-D45
status: affected, version: 15.1X49 prior to 15.1X49-D80
}
metrics:
cvssV3_0: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 7.5
baseSeverity: HIGH
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
version: 3.0
]
workarounds: There are no viable workarounds for this issue.