CVE-2021-0294

Junos OS: QFX5000 Series and EX4600 Series: Enhanced storm control might not work leading to partial Denial of Service

MEDIUM

5.3

CVSS Score

Published: July 15, 2021 at 08:01 PM UTC

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

8 products affected across 2 vendorsJunosQfx5200Qfx5110

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Severity

MEDIUM5.3

Exploit prediction

EPSS 0.9%

Description

A vulnerability in Juniper Networks Junos OS, which only affects the release 18.4R2-S5, where a function is inconsistently implemented on Juniper Networks Junos QFX5000 Series and EX4600 Series, and if "storm-control enhanced" is configured, can lead to the enhanced storm control filter group not be installed. It will cause storm control not to work hence allowing an attacker to cause high CPU usage or packet loss issues by sending a large amount of broadcast or unknown unicast packets arriving the device. This issue affects Juniper Networks QFX5100, QFX5110, QFX5120, QFX5200, QFX5210, EX4600, and EX4650, and QFX5100 with QFX 5e Series image installed. QFX5130 and QFX5220 are not affected from this issue. This issue affects Juniper Networks Junos OS 18.4R2-S5 on QFX5000 Series and EX4600 Series. No other product or platform is affected by this vulnerability.

Affected

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

Junos · Juniper Networks

95%

18.4 r2-s5 18.4R2-S5

juniper-ex4600 (environment) · juniper-ex4650 (environment) · juniper-qfx5100 (environment) · juniper-qfx5110 (environment) · juniper-qfx5120 (environment) · juniper-qfx5200 (environment) · juniper-qfx5210 (environment)

Ex4600 · Juniperdevice

80%

All versions

Ex4650 · Juniperdevice

80%

All versions

Qfx5100 · Juniperdevice

80%

All versions

Qfx5110 · Juniperdevice

80%

All versions