title: Junos OS: QFX and PTX Series: FPC process crashes after J-Flow processes a malformed packet
description: On QFX and PTX Series, receipt of a malformed packet for J-Flow sampling might crash the FPC (Flexible PIC Concentrator) process which causes all interfaces to go down. By continuously sending the offending packet, an attacker can repeatedly crash the FPC process causing a sustained Denial of Service (DoS). This issue affects both IPv4 and IPv6 packet processing. Affected releases are Juniper Networks Junos OS on QFX and PTX Series: 17.4 versions prior to 17.4R2-S1, 17.4R3; 18.1 versions prior to 18.1R3-S1; 18.2 versions prior to 18.2R1-S3, 18.2R2; 17.2X75 versions prior to 17.2X75-D91, 17.2X75-D100.
problem types: DoS
affected:
{
platforms: QFX and PTX Series
product: Junos OS
vendor: Juniper Networks
versions:
lessThan:  17.4R2-S1, 17.4R3, status: affected, version: 17.4, versionType: custom
lessThan: 18.1R3-S1, 18.1R4, status: affected, version: 18.1, versionType: custom
lessThan: 18.2R1-S3, 18.2R2, status: affected, version: 18.2, versionType: custom
lessThan: 17.2X75-D91, 17.2X75-D100, status: affected, version: 17.2X75, versionType: custom
}
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
]
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: Junos OS 17.2X75-D91, 17.2X75-D100, 17.4R2-S1, 17.4R3, 18.1R3-S1, 18.2R1-S3, 18.2R2, 18.2X75-D5, 18.3R1, and all subsequent releases.
workarounds: Disable the functionality of learning of next-hop addresses:
# set services flow-monitoring  (version-ipfix | version9)  template <template-name> nexthop-learning disable