CVE-2021-31361

Junos OS: QFX Series and PTX Series: FPC resource usage increases when certain packets are processed which are being VXLAN encapsulated

MEDIUM

5.3

CVSS Score

Published: October 19, 2021 at 06:16 PM UTC

Updated: June 17, 2026 at 03:51 AM UTC

44 products affected across 2 vendorsJunosQfx5200Qfx5110

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Severity

MEDIUM5.3

Exploit prediction

EPSS 1%

Description

An Improper Check for Unusual or Exceptional Conditions vulnerability combined with Improper Handling of Exceptional Conditions in Juniper Networks Junos OS on QFX Series and PTX Series allows an unauthenticated network based attacker to cause increased FPC CPU utilization by sending specific IP packets which are being VXLAN encapsulated leading to a partial Denial of Service (DoS). Continued receipted of these specific traffic will create a sustained Denial of Service (DoS) condition. This issue affects: Juniper Networks Junos OS on QFX Series: All versions prior to 17.3R3-S11; 17.4 versions prior to 17.4R2-S13, 17.4R3-S4; 18.1 versions prior to 18.1R3-S12; 18.2 versions prior to 18.2R2-S8, 18.2R3-S7; 18.3 versions prior to 18.3R3-S4; 18.4 versions prior to 18.4R1-S8, 18.4R2-S7, 18.4R3-S7; 19.1 versions prior to 19.1R1-S6, 19.1R2-S2, 19.1R3-S4; 19.2 versions prior to 19.2R1-S6, 19.2R3-S2; 19.3 versions prior to 19.3R3-S1; 19.4 versions prior to 19.4R2-S3, 19.4R3-S1; 20.1 versions prior to 20.1R2, 20.1R3; 20.2 versions prior to 20.2R2, 20.2R3; 20.3 versions prior to 20.3R1-S1, 20.3R2. Juniper Networks Junos OS on PTX Series: All versions prior to 18.4R3-S9; 19.1 versions prior to 19.1R3-S6; 19.2 versions prior to 19.2R1-S7, 19.2R3-S3; 19.3 versions prior to 19.3R2-S6, 19.3R3-S3; 19.4 versions prior to 19.4R1-S4, 19.4R3-S5; 20.1 versions prior to 20.1R2-S2, 20.1R3; 20.2 versions prior to 20.2R3-S1; 20.3 versions prior to 20.3R2-S1, 20.3R3; 20.4 versions prior to 20.4R2-S1, 20.4R3; 21.1 versions prior to 21.1R1-S1, 21.1R2.

Affected

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

Junos · Juniper Networks

95%

v < 17.3R3-S11v < 18.4R3-S917.4 ≤ v < 17.4R2-S13, 17.4R3-S418.1 ≤ v < 18.1R3-S1218.2 ≤ v < 18.2R2-S8, 18.2R3-S718.3 ≤ v < 18.3R3-S418.4 ≤ v < 18.4R1-S8, 18.4R2-S7, 18.4R3-S719.1 ≤ v < 19.1R1-S6, 19.1R2-S2, 19.1R3-S419.1 ≤ v < 19.1R3-S619.2 ≤ v < 19.2R1-S6, 19.2R3-S219.2 ≤ v < 19.2R1-S7, 19.2R3-S319.3 ≤ v < 19.3R2-S6, 19.3R3-S319.3 ≤ v < 19.3R3-S119.4 ≤ v < 19.4R1-S4, 19.4R3-S519.4 ≤ v < 19.4R2-S3, 19.4R3-S120.1 ≤ v < 20.1R2, 20.1R320.1 ≤ v < 20.1R2-S2, 20.1R320.2 ≤ v < 20.2R2, 20.2R320.2 ≤ v < 20.2R3-S120.3 ≤ v < 20.3R1-S1, 20.3R220.3 ≤ v < 20.3R2-S1, 20.3R320.4 ≤ v < 20.4R2-S1, 20.4R321.1 ≤ v < 21.1R1-S1, 21.1R217.3 17.3 r1 17.3 r1-s1 17.3 r1-s4 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-s10 17.3 r3-s2 17.3 r3-s3 17.3 r3-s4 17.3 r3-s5 17.3 r3-s6 17.3 r3-s7 17.3 r3-s8 17.3 r3-s917.3r317.3r3-s217.4 17.4 r1 17.4 r1-s1 17.4 r1-s2 17.4 r1-s3 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-s11 17.4 r2-s12 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 17.4 r3-s2 17.4 r3-s3 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-s10 18.1 r3-s11 18.1 r3-s2 18.1 r3-s3 18.1 r3-s4 18.1 r3-s5 18.1 r3-s6 18.1 r3-s7 18.1 r3-s8 18.1 r3-s9 18.2 18.2 r1 18.2 r1-s2 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 r2-s7 18.2 r3 18.2 r3-s1 18.2 r3-s2 18.2 r3-s3 18.2 r3-s4 18.2 r3-s5 18.2 r3-s6 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 18.3 r2-s3 18.3 r2-s4 18.3 r3 18.3 r3-s1 18.3 r3-s2 18.3 r3-s3 18.4 18.4 r1 18.4 r1-s1 18.4 r1-s2 18.4 r1-s3 18.4 r1-s4 18.4 r1-s5 18.4 r1-s6 18.4 r1-s7 18.4 r2 18.4 r2-s1 18.4 r2-s2 18.4 r2-s3 18.4 r2-s4 18.4 r2-s5 18.4 r2-s6 18.4 r2-s7 18.4 r2-s8 18.4 r3 18.4 r3-s1 18.4 r3-s10 18.4 r3-s2 18.4 r3-s3 18.4 r3-s4 18.4 r3-s5 18.4 r3-s6 18.4 r3-s7 18.4 r3-s8 19.1 19.1 r1 19.1 r1-s1 19.1 r1-s2 19.1 r1-s3 19.1 r1-s4 19.1 r1-s5 19.1 r1-s6 19.1 r2 19.1 r2-s1 19.1 r2-s2 19.1 r2-s3 19.1 r3 19.1 r3-s1 19.1 r3-s2 19.1 r3-s3 19.1 r3-s4 19.1 r3-s5 19.2 19.2 r1 19.2 r1-s1 19.2 r1-s2 19.2 r1-s3 19.2 r1-s4 19.2 r1-s5 19.2 r1-s6 19.2 r3 19.2 r3-s1 19.2 r3-s2 19.3 19.3 r1 19.3 r1-s1 19.3 r2 19.3 r2-s1 19.3 r2-s2 19.3 r2-s3 19.3 r2-s4 19.3 r2-s5 19.3 r2-s6 19.3 r3 19.3 r3-s1 19.3 r3-s2 19.4 19.4 r1 19.4 r1-s1 19.4 r1-s2 19.4 r1-s3 19.4 r1-s4 19.4 r2 19.4 r2-s1 19.4 r2-s2 19.4 r2-s3 19.4 r2-s4 19.4 r2-s5 19.4 r3 19.4 r3-s1 19.4 r3-s2 19.4 r3-s3 19.4 r3-s4 20.1 20.1 r1 20.1 r1-s1 20.1 r1-s2 20.1 r1-s3 20.1 r1-s4 20.1 r2 20.1 r2-s1 20.2 20.2 r1 20.2 r1-s1 20.2 r1-s2 20.2 r1-s3 20.2 r2 20.2 r2-s1 20.2 r2-s2 20.2 r2-s3 20.2 r3 20.3 20.3 r1 20.3 r1-s1 20.3 r2 20.4 20.4 r1 20.4 r1-s1 20.4 r2 21.1 21.1 r1

Affected range stops below 17.3R3-S11, so it looks safe — our inference, not a vendor statement

Affected range stops below 17.4R2-S13, 17.4R3-S4, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.1R3-S12, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.2R2-S8, 18.2R3-S7, so it looks safe — our inference, not a vendor statement

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

Affected range stops below 18.4R1-S8, 18.4R2-S7, 18.4R3-S7, so it looks safe — our inference, not a vendor statement

Affected range stops below 18.4R3-S9, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.1R1-S6, 19.1R2-S2, 19.1R3-S4, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.1R3-S6, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.2R1-S6, 19.2R3-S2, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.2R1-S7, 19.2R3-S3, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.3R2-S6, 19.3R3-S3, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.3R3-S1, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.4R1-S4, 19.4R3-S5, so it looks safe — our inference, not a vendor statement

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

Affected range stops below 20.1R2, 20.1R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 20.1R2-S2, 20.1R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 20.2R2, 20.2R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 20.2R3-S1, so it looks safe — our inference, not a vendor statement

Affected range stops below 20.3R1-S1, 20.3R2, so it looks safe — our inference, not a vendor statement

Affected range stops below 20.3R2-S1, 20.3R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 20.4R2-S1, 20.4R3, so it looks safe — our inference, not a vendor statement

Affected range stops below 21.1R1-S1, 21.1R2, so it looks safe — our inference, not a vendor statement

juniper-ptx1000 (environment) · juniper-ptx1000-72q (environment) · juniper-ptx10000 (environment) · juniper-ptx10001 (environment) · juniper-ptx10001-36mr (environment) · juniper-ptx100016 (environment) · juniper-ptx10002 (environment) · juniper-ptx10002-60c (environment) · juniper-ptx10003 (environment) · juniper-ptx10003-160c (environment) · juniper-ptx10003-80c (environment) · juniper-ptx10003-81cd (environment) · juniper-ptx10004 (environment) · juniper-ptx10008 (environment) · juniper-ptx10016 (environment) · juniper-ptx3000 (environment) · juniper-ptx5000 (environment) · juniper-qfx10000 (environment) · juniper-qfx10002 (environment) · juniper-qfx10002-32q (environment) · juniper-qfx10002-60c (environment) · juniper-qfx10002-72q (environment) · juniper-qfx10008 (environment) · juniper-qfx10016 (environment) · juniper-qfx10k (environment) · juniper-qfx3000-g (environment) · juniper-qfx3000-m (environment) · juniper-qfx3008-i (environment) · juniper-qfx3100 (environment) · juniper-qfx3500 (environment) · juniper-qfx3600 (environment) · juniper-qfx3600-i (environment) · juniper-qfx5100 (environment) · juniper-qfx5100-96s (environment) · juniper-qfx5110 (environment) · juniper-qfx5120 (environment) · juniper-qfx5130 (environment) · juniper-qfx5200 (environment) · juniper-qfx5200-32c (environment) · juniper-qfx5200-48y (environment) · juniper-qfx5210 (environment) · juniper-qfx5210-64c (environment) · juniper-qfx5220 (environment)

Ptx1000 · Juniperdevice

80%

All versions

Ptx1000-72Q · Juniperdevice

80%

All versions

Ptx10000 · Juniperdevice

80%

All versions

Ptx10001 · Juniperdevice

80%

All versions