title: Junos OS: MX series/EX9200 Series: IPv6 DDoS protection does not work as expected.
description: On Juniper Networks MX Series and EX9200 Series, in a certain condition the IPv6 Distributed Denial of Service (DDoS) protection might not take affect when it reaches the threshold condition. The DDoS protection allows the device to continue to function while it is under DDoS attack, protecting both the Routing Engine (RE) and the Flexible PIC Concentrator (FPC) during the DDoS attack. When this issue occurs, the RE and/or the FPC can become overwhelmed, which could disrupt network protocol operations and/or interrupt traffic. This issue does not affect IPv4 DDoS protection. This issue affects MX Series and EX9200 Series with Trio-based PFEs (Packet Forwarding Engines). Please refer to https://kb.juniper.net/KB25385 for the list of Trio-based PFEs. This issue affects Juniper Networks Junos OS on MX series and EX9200 Series: 17.2 versions prior to 17.2R3-S4; 17.2X75 versions prior to 17.2X75-D102, 17.2X75-D110; 17.3 versions prior to 17.3R3-S8; 17.4 versions prior to 17.4R2-S11, 17.4R3-S2; 18.2 versions prior to 18.2R2-S7, 18.2R3, 18.2R3-S3; 18.2X75 versions prior to 18.2X75-D30; 18.3 versions prior to 18.3R2-S4, 18.3R3-S2.
problem types: CWE-794: Incomplete Filtering of Multiple Instances of Special Elements
affected:
{
platforms: MX series/EX9200 Series
product: Junos OS
vendor: Juniper Networks
versions:
lessThan: 17.2R3-S4, status: affected, version: 17.2, versionType: custom
lessThan: 17.2X75-D102, 17.2X75-D110, status: affected, version: 17.2X75, versionType: custom
lessThan: 17.3R3-S8, status: affected, version: 17.3, versionType: custom
lessThan: 17.4R2-S11, 17.4R3-S2, status: affected, version: 17.4, versionType: custom
lessThan: 18.2R2-S7, 18.2R3, 18.2R3-S3, status: affected, version: 18.2, versionType: custom
lessThan: 18.2X75-D30, status: affected, version: 18.2X75, versionType: custom
lessThan: 18.3R2-S4, 18.3R3-S2, status: affected, version: 18.3, versionType: custom
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: LOW
baseScore: 5.3
baseSeverity: MEDIUM
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:L
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 17.2R3-S4, 17.2X75-D102, 17.2X75-D110, 17.3R3-S8, 17.4R2-S11, 17.4R3-S2, 18.2R2-S7, 18.2R3, 18.2R3-S3, 18.2X75-D30, 18.3R2-S4, 18.3R3-S2, 18.4R1, and all subsequent releases.
workarounds: There are no viable workarounds for this issue.