CVE-2020-1633

Junos OS: MX Series: Crafted packets traversing a Broadband Network Gateway (BNG) configured with IPv6 NDP proxy could lead to Denial of Service

MEDIUM

6.5

CVSS Score

Published: April 9, 2020 at 11:09 PM UTC

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

16 products affected across 2 vendorsJunosMx480Mx960

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Severity

MEDIUM6.5

Exploit prediction

EPSS 0.5%

Description

Due to a new NDP proxy feature for EVPN leaf nodes introduced in Junos OS 17.4, crafted NDPv6 packets could transit a Junos device configured as a Broadband Network Gateway (BNG) and reach the EVPN leaf node, causing a stale MAC address entry. This could cause legitimate traffic to be discarded, leading to a Denial of Service (DoS) condition. This issue only affects Junos OS 17.4 and later releases. Prior releases do not support this feature and are unaffected by this vulnerability. This issue only affects IPv6. IPv4 ARP proxy is unaffected by this vulnerability. This issue affects Juniper Networks Junos OS: 17.4 versions prior to 17.4R2-S9, 17.4R3 on MX Series; 18.1 versions prior to 18.1R3-S9 on MX Series; 18.2 versions prior to 18.2R2-S7, 18.2R3-S3 on MX Series; 18.2X75 versions prior to 18.2X75-D33, 18.2X75-D411, 18.2X75-D420, 18.2X75-D60 on MX Series; 18.3 versions prior to 18.3R1-S7, 18.3R2-S3, 18.3R3 on MX Series; 18.4 versions prior to 18.4R1-S5, 18.4R2-S2, 18.4R3 on MX Series; 19.1 versions prior to 19.1R1-S4, 19.1R2 on MX Series; 19.2 versions prior to 19.2R1-S3, 19.2R2 on MX Series.

Affected

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

Junos · Juniper Networks

95%

17.4 ≤ v < 17.4R2-S9, 17.4R318.1 ≤ v < 18.1R3-S918.2 ≤ v < 18.2R2-S7, 18.2R3-S318.2X75 ≤ v < 18.2X75-D33, 18.2X75-D411, 18.2X75-D420, 18.2X75-D6018.3 ≤ v < 18.3R1-S7, 18.3R2-S3, 18.3R318.4 ≤ v < 18.4R1-S5, 18.4R2-S2, 18.4R319.1 ≤ v < 19.1R1-S4, 19.1R219.2 ≤ v < 19.2R1-S3, 19.2R217.4 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-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 18.1 18.1 r2 18.1 r2-s1 18.1 r2-s2 18.1 r2-s4 18.1 r3 18.1 r3-s1 18.1 r3-s2 18.1 r3-s3 18.1 r3-s4 18.1 r3-s6 18.1 r3-s7 18.1 r3-s8 18.2 18.2 r1 18.2 r1-s3 18.2 r1-s5 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 d20 18.2x75 d30 18.3 18.3 r1 18.3 r1-s1 18.3 r1-s2 18.3 r1-s3 18.3 r1-s4 18.3 r1-s5 18.3 r1-s6 18.3 r2 18.3 r2-s1 18.3 r2-s2 18.4 18.4 r1 18.4 r1-s1 18.4 r1-s2 18.4 r1-s3 18.4 r1-s4 18.4 r2 18.4 r2-s1 19.1 19.1 r1 19.1 r1-s1 19.1 r1-s2 19.1 r1-s3 19.2 19.2 r1 19.2 r1-s1 19.2 r1-s2

Affected range stops below 17.4R2-S9, 17.4R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.1R3-S9, so it looks safe — our inference, not a vendor statement

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

Affected range stops below 18.2X75-D33, 18.2X75-D411, 18.2X75-D420, 18.2X75-D60, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.3R1-S7, 18.3R2-S3, 18.3R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.4R1-S5, 18.4R2-S2, 18.4R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.1R1-S4, 19.1R2, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.2R1-S3, 19.2R2, so it looks safe — our inference, not a vendor statement

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)

Mx10 · Juniperdevice

80%

All versions

Mx10000 · Juniperdevice

80%

All versions

Mx10003 · Juniperdevice

80%

All versions

Mx104 · Juniperdevice

80%

All versions