CVE-2021-0236

mediumpriority · track · 27EPSS 0.008 · 58 %ileEUUS

grimoire priorityP3 · Track

Exploitable?

—

no known exploitation

Likely / severe?

0.85% (58th) EPSS

CVSS 6.8 · medium

Is it mine?

21 products

Check your exposure

Who says so?

3 sources

cnnvd · enisa_euvd · nvd

EPSS · scored 2026-10-27

Due to an improper check for unusual or exceptional conditions in Juniper Networks Junos OS and Junos OS Evolved the Routing Protocol Daemon (RPD) service, upon receipt of a specific matching BGP packet meeting a specific term in the flowspec configuration, crashes and restarts causing a Denial of Service (DoS). Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition. This issue affects only Multiprotocol BGP (MP-BGP) VPNv6 FlowSpec deployments. This issue affects: Juniper Networks Junos OS: 18.4 versions prior to 18.4R1-S8, 18.4R2-S7, 18.4R3-S7; 19.1 versions prior to 19.1R2-S2, 19.1R3-S4; 19.2 versions prior to 19.2R1-S6, 19.2R3-S2; 19.3 versions prior to 19.3R3-S2; 19.4 versions prior to 19.4R2-S4, 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 Evolved: All versions after 18.4R1-EVO prior to 20.3R2-EVO. This issue does not affect: Juniper Networks Junos OS versions prior to 18.4R1. Juniper Networks Junos OS Evolved versions prior to 18.4R1-EVO.

cvss

Technical severity, 0–10. One row per scoring source.

6.8

010

base score 0–10 · higher = more severe · hover a vector to decode

v2.06.8mediumAV:N/AC:L/Au:S/C:N/I:N/A:Cprimary · NVD / NIST USexploitability 8 · impact 6.9

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hsecondary · ENISA EU

v3.16.5mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:Hsecondary · sirt@juniper.net USexploitability 2.8 · impact 3.6

v3.16mediumCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H/E:Usecondary · CVSS-BT (t0sche)

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-754USprimary

affected products (21)

Products and version ranges known to be affected.

Juniper Networks Junos OS18.4 → 18.4R1-S8, 18.4R2-S7, 18.4R3-S7enisa_euvdEU
Juniper Networks Junos OS19.1 → 19.1R2-S2, 19.1R3-S4enisa_euvdEU
Juniper Networks Junos OS19.2 → 19.2R1-S6, 19.2R3-S2enisa_euvdEU
Juniper Networks Junos OS19.3 → 19.3R3-S2enisa_euvdEU
Juniper Networks Junos OS19.4 → 19.4R2-S4, 19.4R3-S1enisa_euvdEU
Juniper Networks Junos OS20.1 → 20.1R2, 20.1R3, 20.1R3-EVOenisa_euvdEU
Juniper Networks Junos OS20.2 → 20.2R2, 20.2R3, 20.2R3-EVOenisa_euvdEU
Juniper Networks Junos OS20.3 → 20.3R1-S1, 20.3R2, 20.3R2-EVOenisa_euvdEU
Juniper Networks Junos OS Evolved20.3-EVO → 20.3R2-EVOenisa_euvdEU
juniper junos= 18.4nvdUScpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:*
juniper junos= 19.1nvdUScpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:*
juniper junos= 19.2nvdUScpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:*
juniper junos= 19.3nvdUScpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:*
juniper junos= 19.4nvdUScpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:*
juniper junos= 20.1nvdUScpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:*
juniper junos= 20.2nvdUScpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:*
juniper junos= 20.3nvdUScpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:*
juniper junos os evolved= 19.1nvdUScpe:2.3:o:juniper:junos_os_evolved:*:*:*:*:*:*:*:*
juniper junos os evolved= 19.2nvdUScpe:2.3:o:juniper:junos_os_evolved:*:*:*:*:*:*:*:*
juniper junos os evolved= 19.3nvdUScpe:2.3:o:juniper:junos_os_evolved:*:*:*:*:*:*:*:*

showing 20 of 21

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd nvd NVD CVE.org MITRE

published 2021-04-22modified 2026-06-17

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references (7)

External citations — patches, advisories, analysis.

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