CVE-2021-0203

Junos OS: EX and QFX5K Series: Storm Control does not work as expected when Redundant Trunk Group is configured

HIGH

8.6

CVSS Score

Published: January 15, 2021 at 05:35 PM UTC

Updated: June 17, 2026 at 03:29 AM UTC

17 products affected across 2 vendorsJunosQfx5200Qfx5110

Using Junos OS by Juniper Networks?

Get instant alerts when new vulnerabilities affect Junos OS - before attackers find them.

Real-time alertsTrack your software stackFree plan available

Start Free Sign In

Severity

HIGH8.6

Exploit prediction

EPSS 1%

Description

On Juniper Networks EX and QFX5K Series platforms configured with Redundant Trunk Group (RTG), Storm Control profile applied on the RTG interface might not take affect when it reaches the threshold condition. Storm Control enables the device to monitor traffic levels and to drop broadcast, multicast, and unknown unicast packets when a specified traffic level is exceeded, thus preventing packets from proliferating and degrading the LAN. Note: this issue does not affect EX2200, EX3300, EX4200, and EX9200 Series. This issue affects Juniper Networks Junos OS on EX Series and QFX5K Series: 15.1 versions prior to 15.1R7-S7; 16.1 versions prior to 16.1R7-S8; 17.2 versions prior to 17.2R3-S4; 17.3 versions prior to 17.3R3-S8; 17.4 versions prior to 17.4R2-S11, 17.4R3-S2; 18.1 versions prior to 18.1R3-S10; 18.2 versions prior to 18.2R3-S5; 18.3 versions prior to 18.3R2-S4, 18.3R3-S2; 18.4 versions prior to 18.4R2-S5, 18.4R3-S3; 19.1 versions prior to 19.1R2-S2, 19.1R3-S2; 19.2 versions prior to 19.2R1-S5, 19.2R2-S1, 19.2R3; 19.3 versions prior to 19.3R2-S4, 19.3R3; 19.4 versions prior to 19.4R1-S3, 19.4R2-S1, 19.4R3; 20.1 versions prior to 20.1R1-S2, 20.1R2.

Affected

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

Junos · Juniper Networks

95%

15.1 ≤ v < 15.1R7-S716.1 ≤ v < 16.1R7-S817.2 ≤ v < 17.2R3-S417.3 ≤ v < 17.3R3-S817.4 ≤ v < 17.4R2-S11, 17.4R3-S218.1 ≤ v < 18.1R3-S1018.2 ≤ v < 18.2R3-S518.3 ≤ v < 18.3R2-S4, 18.3R3-S218.4 ≤ v < 18.4R2-S5, 18.4R3-S319.1 ≤ v < 19.1R2-S2, 19.1R3-S219.2 ≤ v < 19.2R1-S5, 19.2R2-S1, 19.2R319.3 ≤ v < 19.3R2-S4, 19.3R319.4 ≤ v < 19.4R1-S3, 19.4R2-S1, 19.4R320.1 ≤ v < 20.1R1-S2, 20.1R215.1 15.1 a1 15.1 f 15.1 f1 15.1 f2 15.1 f2-s1 15.1 f2-s2 15.1 f2-s3 15.1 f2-s4 15.1 f3 15.1 f4 15.1 f5 15.1 f5-s7 15.1 f6 15.1 f6-s1 15.1 f6-s12 15.1 f6-s2 15.1 f6-s3 15.1 f6-s4 15.1 f6-s7 15.1 f7 15.1 r1 15.1 r2 15.1 r3 15.1 r4 15.1 r4-s7 15.1 r4-s8 15.1 r4-s9 15.1 r5 15.1 r5-s1 15.1 r5-s5 15.1 r5-s6 15.1 r6 15.1 r6-s1 15.1 r6-s2 15.1 r6-s6 15.1 r7 15.1 r7-s1 15.1 r7-s2 15.1 r7-s3 15.1 r7-s4 15.1 r7-s5 15.1 r7-s6 16.1 16.1 r1 16.1 r2 16.1 r3 16.1 r3-s10 16.1 r3-s11 16.1 r4 16.1 r4-s12 16.1 r4-s2 16.1 r4-s3 16.1 r4-s4 16.1 r4-s6 16.1 r5 16.1 r5-s4 16.1 r6-s1 16.1 r6-s6 16.1 r7 16.1 r7-s2 16.1 r7-s3 16.1 r7-s4 16.1 r7-s5 16.1 r7-s6 16.1 r7-s7 17.2 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 17.3 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 18.1 18.1 r1 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 18.1 r3-s9 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 18.2 r3-s3 18.2 r3-s4 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 18.4 18.4 r1 18.4 r1-s1 18.4 r1-s2 18.4 r1-s5 18.4 r1-s6 18.4 r2 18.4 r2-s1 18.4 r2-s2 18.4 r2-s3 18.4 r2-s4 18.4 r3 18.4 r3-s1 18.4 r3-s2 19.1 19.1 r1 19.1 r1-s1 19.1 r1-s2 19.1 r1-s3 19.1 r1-s4 19.1 r2 19.1 r2-s1 19.1 r3 19.1 r3-s1 19.2 19.2 r1 19.2 r1-s1 19.2 r1-s2 19.2 r1-s3 19.2 r1-s4 19.2 r2 19.3 19.3 r1 19.3 r1-s1 19.3 r2 19.3 r2-s1 19.3 r2-s2 19.3 r2-s3 19.4 19.4 r1 19.4 r1-s1 19.4 r1-s2 19.4 r2 20.1 20.1 r1 20.1 r1-s1

Affected range stops below 15.1R7-S7, so it looks safe — our inference, not a vendor statement

Affected range stops below 16.1R7-S8, so it looks safe — our inference, not a vendor statement

Affected range stops below 17.2R3-S4, 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 18.1R3-S10, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.2R3-S5, 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

Affected range stops below 18.4R2-S5, 18.4R3-S3, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.1R2-S2, 19.1R3-S2, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.2R1-S5, 19.2R2-S1, 19.2R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.3R2-S4, 19.3R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.4R1-S3, 19.4R2-S1, 19.4R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 20.1R1-S2, 20.1R2, so it looks safe — our inference, not a vendor statement

juniper-ex2300 (environment) · juniper-ex2300-c (environment) · juniper-ex2300m (environment) · juniper-ex3400 (environment) · juniper-ex4300 (environment) · juniper-ex4300m (environment) · juniper-ex4600 (environment) · juniper-ex4650 (environment) · juniper-ex9250 (environment) · juniper-qfx5100 (environment) · juniper-qfx5110 (environment) · juniper-qfx5120 (environment) · juniper-qfx5130 (environment) · juniper-qfx5200 (environment) · juniper-qfx5210 (environment) · juniper-qfx5220 (environment)

Ex2300 · Juniperdevice

80%

All versions

Ex2300-C · Juniperdevice

80%

All versions

Ex2300M · Juniperdevice

80%

All versions

Ex3400 · Juniperdevice

80%

All versions