CVE-2021-0211

Junos OS and Junos OS Evolved: Upon receipt of a specific BGP FlowSpec message network traffic may be disrupted.

CRITICAL

CVSS Score

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

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

87 products affected across 2 vendorsJunosJunos OS EvolvedSRX5800

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Severity

CRITICAL10

Exploit prediction

EPSS 1%

Description

An improper check for unusual or exceptional conditions in Juniper Networks Junos OS and Junos OS Evolved Routing Protocol Daemon (RPD) service allows an attacker to send a valid BGP FlowSpec message thereby causing an unexpected change in the route advertisements within the BGP FlowSpec domain leading to disruptions in network traffic causing a Denial of Service (DoS) condition. Continued receipt of these update messages will cause a sustained Denial of Service condition. This issue affects Juniper Networks: Junos OS: All versions prior to 17.3R3-S10 with the exceptions of 15.1X49-D240 on SRX Series and 15.1R7-S8 on EX Series; 17.3 versions prior to 17.3R3-S10; 17.4 versions prior to 17.4R2-S12, 17.4R3-S4; 18.1 versions prior to 18.1R3-S12; 18.2 versions prior to 18.2R2-S8, 18.2R3-S6; 18.3 versions prior to 18.3R3-S4; 18.4 versions prior to 18.4R1-S8, 18.4R2-S6, 18.4R3-S6; 19.1 versions prior to 19.1R1-S6, 19.1R2-S2, 19.1R3-S3; 19.2 versions prior to 19.2R3-S1; 19.3 versions prior to 19.3R2-S5, 19.3R3-S1; 19.4 versions prior to 19.4R1-S3, 19.4R2-S3, 19.4R3; 20.1 versions prior to 20.1R2; 20.2 versions prior to 20.2R1-S3 20.2R2; 20.3 versions prior to 20.3R1-S1, 20.3R2. Junos OS Evolved: All versions prior to 20.3R1-S1-EVO, 20.3R2-EVO.

Affected

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

Junos OS Evolved · Juniper

95%

19.2 r1 19.2 r2 19.3 r2 19.4 r1 19.4 r2 19.4 r2-s1 20.1 20.1 r1 20.2 20.3 r1

Junos · Juniper Networks

95%

15.1 ≤ v < 15.1R7-S815.1X49 ≤ v < 15.1X490-D24017.3 ≤ v < 17.3R3-S1017.4 ≤ v < 17.4R2-S12, 17.4R3-S418.1 ≤ v < 18.1R3-S1218.2 ≤ v < 18.2R2-S8, 18.2R3-S618.3 ≤ v < 18.3R3-S418.4 ≤ v < 18.4R1-S8, 18.4R2-S6, 18.4R3-S619.1 ≤ v < 19.1R1-S6, 19.1R2-S2, 19.1R3-S319.2 ≤ v < 19.2R3-S119.3 ≤ v < 19.3R2-S5, 19.3R3-S119.4 ≤ v < 19.4R1-S3, 19.4R2-S3, 19.4R320.1 ≤ v < 20.1R220.2 ≤ v < 20.2R1-S3 20.2R220.3 ≤ v < 20.3R1-S1, 20.3R215.1 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-s10 15.1 f6-s12 15.1 f6-s2 15.1 f6-s3 15.1 f6-s4 15.1 f6-s5 15.1 f6-s6 15.1 f6-s7 15.1 f6-s8 15.1 f6-s9 15.1 f7 15.1 r 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-s3 15.1 r5-s5 15.1 r5-s6 15.1 r6 15.1 r6-s1 15.1 r6-s2 15.1 r6-s3 15.1 r6-s4 15.1 r6-s6 15.1 r7 15.1 r7-s1 15.1 r7-s10 15.1 r7-s11 15.1 r7-s2 15.1 r7-s3 15.1 r7-s4 15.1 r7-s5 15.1 r7-s6 15.1 r7-s7 15.1X4915.1x4915.1x49 d10 15.1x49 d100 15.1x49 d110 15.1x49 d120 15.1x49 d13015.1x49 d13115.1x49 d140 15.1x49 d15 15.1x49 d150 15.1x49 d160 15.1x49 d170 15.1x49 d180 15.1x49 d190 15.1x49 d20 15.1x49 d200 15.1x49 d210 15.1x49 d25 15.1x49 d30 15.1x49 d35 15.1x49 d40 15.1x49 d45 15.1x49 d50 15.1x49 d55 15.1x49 d60 15.1x49 d65 15.1x49 d70 15.1x49 d75 15.1x49 d80 15.1x49 d9015.1x49-d14015.1x49-d15015.1x49-d16015.1x49-d3015.1x49-d6017.3 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 17.3 r3-s8 17.3 r3-s9 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-s11 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-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 r2-s7 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 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 r3 18.4 r3-s1 18.4 r3-s2 18.4 r3-s3 18.4 r3-s4 18.4 r3-s5 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 r2 19.1 r2-s1 19.1 r3 19.1 r3-s1 19.1 r3-s2 19.2 19.2 r1 19.2 r1-s1 19.2 r1-s2 19.2 r1-s3 19.2 r1-s4 19.2 r2 19.2 r3 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 r3 19.4 19.4 r1 19.4 r1-s1 19.4 r1-s2 19.4 r2 19.4 r2-s1 19.4 r2-s2 20.1 20.1 r1 20.1 r1-s1 20.1 r1-s2 20.1 r1-s3 20.2 20.2 r1 20.2 r1-s1 20.2 r1-s2 20.3 20.3 r1

Affected range stops below 15.1R7-S8, so it looks safe — our inference, not a vendor statement

Affected range stops below 15.1X490-D240, so it looks safe — our inference, not a vendor statement

Affected range stops below 17.3R3-S10, so it looks safe — our inference, not a vendor statement

Affected range stops below 17.4R2-S12, 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-S6, 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-S6, 18.4R3-S6, so it looks safe — our inference, not a vendor statement

Affected range stops below 19.1R1-S6, 19.1R2-S2, 19.1R3-S3, so it looks safe — our inference, not a vendor statement

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

Affected range stops below 19.3R2-S5, 19.3R3-S1, so it looks safe — our inference, not a vendor statement

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

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

Affected range stops below 20.2R1-S3 20.2R2, 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

juniper-ex-rps (environment) · juniper-ex2200 (environment) · juniper-ex2200-c (environment) · juniper-ex2200-vc (environment) · juniper-ex2300 (environment) · juniper-ex2300-c (environment) · juniper-ex2300m (environment) · juniper-ex3200 (environment) · juniper-ex3300 (environment) · juniper-ex3300-vc (environment) · juniper-ex3400 (environment) · juniper-ex4200 (environment) · juniper-ex4200-vc (environment) · juniper-ex4300 (environment) · juniper-ex4300-24p (environment) · juniper-ex4300-24p-s (environment) · juniper-ex4300-24t (environment) · juniper-ex4300-24t-s (environment) · juniper-ex4300-32f (environment) · juniper-ex4300-32f-dc (environment) · juniper-ex4300-32f-s (environment) · juniper-ex4300-48mp (environment) · juniper-ex4300-48mp-s (environment) · juniper-ex4300-48p (environment) · juniper-ex4300-48p-s (environment) · juniper-ex4300-48t (environment) · juniper-ex4300-48t-afi (environment) · juniper-ex4300-48t-dc (environment) · juniper-ex4300-48t-dc-afi (environment) · juniper-ex4300-48t-s (environment) · juniper-ex4300-48tafi (environment) · juniper-ex4300-48tdc (environment) · juniper-ex4300-48tdc-afi (environment) · juniper-ex4300-mp (environment) · juniper-ex4300-vc (environment) · juniper-ex4300m (environment) · juniper-ex4400 (environment) · juniper-ex4500 (environment) · juniper-ex4500-vc (environment) · juniper-ex4550 (environment) · juniper-ex4550-vc (environment) · juniper-ex4600 (environment) · juniper-ex4600-vc (environment) · juniper-ex4650 (environment) · juniper-ex6200 (environment) · juniper-ex6210 (environment) · juniper-ex8200 (environment) · juniper-ex8200-vc (environment) · juniper-ex8208 (environment) · juniper-ex8216 (environment) · juniper-ex9200 (environment) · juniper-ex9204 (environment) · juniper-ex9208 (environment) · juniper-ex9214 (environment) · juniper-ex9250 (environment) · juniper-ex9251 (environment) · juniper-ex9253 (environment) · juniper-srx100 (environment) · juniper-srx110 (environment) · juniper-srx1400 (environment) · juniper-srx1500 (environment) · juniper-srx210 (environment) · juniper-srx220 (environment) · juniper-srx240 (environment) · juniper-srx240h2 (environment) · juniper-srx300 (environment) · juniper-srx320 (environment) · juniper-srx340 (environment) · juniper-srx3400 (environment) · juniper-srx345 (environment) · juniper-srx3600 (environment) · juniper-srx380 (environment) · juniper-srx4000 (environment) · juniper-srx4100 (environment) · juniper-srx4200 (environment) · juniper-srx4600 (environment) · juniper-srx5000 (environment) · juniper-srx5400 (environment) · juniper-srx550 (environment) · juniper-srx550-hm (environment) · juniper-srx550m (environment) · juniper-srx5600 (environment) · juniper-srx5800 (environment) · juniper-srx650 (environment)

Junos OS Evolved · Juniper Networks

60%

v < 20.3R1-S1-EVO, 20.3R2-EVO

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

Ex Rps · Juniperdevice

80%

All versions

Ex2200 · Juniperdevice

80%

All versions

Ex2200-C · Juniperdevice

80%