CVE-2020-1665

Junos OS: MX series/EX9200 Series: IPv6 DDoS protection does not work as expected.

MEDIUM

5.3

CVSS Score

Published: October 16, 2020 at 08:31 PM UTC

Updated: June 17, 2026 at 03:02 AM UTC

17 products affected across 2 vendorsJunosMx480Mx960

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Severity

MEDIUM5.3

Exploit prediction

EPSS 1%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Junos · Juniper Networks

95%

17.2 ≤ v < 17.2R3-S417.2X75 ≤ v < 17.2X75-D102, 17.2X75-D11017.3 ≤ v < 17.3R3-S817.4 ≤ v < 17.4R2-S11, 17.4R3-S218.2 ≤ v < 18.2R2-S7, 18.2R3, 18.2R3-S318.2X75 ≤ v < 18.2X75-D3018.3 ≤ v < 18.3R2-S4, 18.3R3-S217.2 17.2 r1 17.2 r1-s1 17.2 r1-s2 17.2 r1-s3 17.2 r1-s4 17.2 r1-s5 17.2 r1-s7 17.2 r1-s8 17.2 r2 17.2 r2-s11 17.2 r2-s6 17.2 r2-s7 17.2 r3-s1 17.2 r3-s2 17.2 r3-s3 17.2X7517.2x7517.2x75 d50 17.2x75 d70 17.2x75 d92 17.3 17.3 r1-s1 17.3 r2 17.3 r2-s1 17.3 r2-s2 17.3 r2-s3 17.3 r2-s4 17.3 r2-s5 17.3 r3 17.3 r3-s1 17.3 r3-s2 17.3 r3-s3 17.3 r3-s4 17.3 r3-s7 17.4 17.4 r1 17.4 r1-s1 17.4 r1-s2 17.4 r1-s4 17.4 r1-s5 17.4 r1-s6 17.4 r1-s7 17.4 r2 17.4 r2-s1 17.4 r2-s10 17.4 r2-s2 17.4 r2-s3 17.4 r2-s4 17.4 r2-s5 17.4 r2-s6 17.4 r2-s7 17.4 r2-s8 17.4 r2-s9 17.4 r3 17.4 r3-s1 18.2 18.2 r1 18.2 r1-s3 18.2 r1-s4 18.2 r1-s5 18.2 r2 18.2 r2-s1 18.2 r2-s2 18.2 r2-s3 18.2 r2-s4 18.2 r2-s5 18.2 r2-s6 18.2 r3 18.2 r3-s1 18.2 r3-s2 18.2X7518.2x7518.2x75 d1218.2x75 d20 18.3 18.3 r1 18.3 r1-s1 18.3 r1-s2 18.3 r1-s3 18.3 r1-s5 18.3 r1-s6 18.3 r2 18.3 r2-s1 18.3 r2-s2 18.3 r2-s3 18.3 r3 18.3 r3-s1

Affected range stops below 17.2R3-S4, so it looks safe — our inference, not a vendor statement

Affected range stops below 17.2X75-D102, 17.2X75-D110, so it looks safe — our inference, not a vendor statement

Affected range stops below 17.3R3-S8, so it looks safe — our inference, not a vendor statement

Affected range stops below 17.4R2-S11, 17.4R3-S2, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.2R2-S7, 18.2R3, 18.2R3-S3, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.2X75-D30, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.3R2-S4, 18.3R3-S2, so it looks safe — our inference, not a vendor statement

juniper-ex9200 (environment) · juniper-mx10 (environment) · juniper-mx10000 (environment) · juniper-mx10003 (environment) · juniper-mx104 (environment) · juniper-mx150 (environment) · juniper-mx2008 (environment) · juniper-mx2010 (environment) · juniper-mx2020 (environment) · juniper-mx204 (environment) · juniper-mx240 (environment) · juniper-mx40 (environment) · juniper-mx480 (environment) · juniper-mx5 (environment) · juniper-mx80 (environment) · juniper-mx960 (environment)

Ex9200 · Juniperdevice

80%

All versions

Mx10 · Juniperdevice

80%

All versions

Mx10000 · Juniperdevice

80%

All versions

Mx10003 · Juniperdevice

80%

All versions