title: Junos OS: PTX Series, QFX10K Series: Upon receipt of specific packets BFD sessions might flap due to DDoS policer implementation in Packet Forwarding Engine
description: Due to an Improper Initialization vulnerability in Juniper Networks Junos OS on PTX platforms and QFX10K Series with Paradise (PE) chipset-based line cards, ddos-protection configuration changes made from the CLI will not take effect as expected beyond the default DDoS (Distributed Denial of Service) settings in the Packet Forwarding Engine (PFE). This may cause BFD sessions to flap when a high rate of specific packets are received. Flapping of BFD sessions in turn may impact routing protocols and network stability, leading to a Denial of Service (DoS) condition. Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition. This issue affects only the following platforms with Paradise (PE) chipset-based line cards: PTX1000, PTX3000 (NextGen), PTX5000, PTX10008, PTX10016 Series and QFX10002 Series. This issue affects: Juniper Networks Junos OS 17.4 versions prior to 17.4R3-S5 on PTX Series, QFX10K Series; 18.2 versions prior to 18.2R3-S8 on PTX Series, QFX10K Series; 18.3 versions prior to 18.3R3-S5 on PTX Series, QFX10K Series; 18.4 versions prior to 18.4R2-S8 on PTX Series, QFX10K Series; 19.1 versions prior to 19.1R3-S5 on PTX Series, QFX10K Series; 19.2 versions prior to 19.2R3-S2 on PTX Series, QFX10K Series; 19.3 versions prior to 19.3R3-S2 on PTX Series, QFX10K Series; 19.4 versions prior to 19.4R3-S2 on PTX Series, QFX10K Series; 20.1 versions prior to 20.1R3 on PTX Series, QFX10K Series; 20.2 versions prior to 20.2R2-S3, 20.2R3 on PTX Series, QFX10K Series; 20.3 versions prior to 20.3R2 on PTX Series, QFX10K Series; 20.4 versions prior to 20.4R2 on PTX Series, QFX10K Series.
problem types: CWE-665 Improper Initialization
affected:
{
platforms: PTX Series, QFX10K Series
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 17.4R3-S5, status: affected, version: 17.4, versionType: custom
lessThan: 18.2R3-S8, status: affected, version: 18.2, versionType: custom
lessThan: 18.3R3-S5, status: affected, version: 18.3, versionType: custom
lessThan: 18.4R2-S8, status: affected, version: 18.4, versionType: custom
lessThan: 19.1R3-S5, status: affected, version: 19.1, versionType: custom
lessThan: 19.2R3-S2, status: affected, version: 19.2, versionType: custom
lessThan: 19.3R3-S2, status: affected, version: 19.3, versionType: custom
lessThan: 19.4R3-S2, status: affected, version: 19.4, versionType: custom
lessThan: 20.1R3, status: affected, version: 20.1, versionType: custom
lessThan: 20.2R2-S3, 20.2R3, status: affected, version: 20.2, versionType: custom
lessThan: 20.3R2, 20.3R3, status: affected, version: 20.3, versionType: custom
lessThan: 20.4R2, status: affected, version: 20.4, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 7.5
baseSeverity: HIGH
confidentialityImpact: NONE
integrityImpact: NONE
privilegesRequired: NONE
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
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: Junos OS 17.4R3-S5, 18.2R3-S8, 18.3R3-S5, 18.4R2-S8, 19.1R3-S5, 19.2R3-S2, 19.3R3-S2, 19.4R3-S2, 20.1R3, 20.2R2-S3, 20.2R3, 20.3R2, 20.4R2, 21.1R1, and all subsequent releases.
workarounds: The default ukern policer rate can be reduced by the CLI command:
set system ddos-protection protocols <protocol-group> <aggregate | packet-type> bandwidth <packets-per-second> burst <size>