CVE detail

CVE-2021-0211 — CVE-2021-0211

Published 2021-01-15 · Modified 2026-06-17 · Vendor juniper · Product junos · Source nvd
CRITICAL
severity
CVSS-derived band
10.0
CVSS v3
0–10 scale
0.0132
EPSS probability
exploitation probability, 30d
68.0%
EPSS percentile
percentile vs all CVEs
NOT LISTED
CISA KEV
known exploited catalog

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.

Remediation

vendor remediation guidance

The following software releases have been updated to resolve this specific issue: Junos OS: 15.1R7-S8, 15.1X49-D240, 17.3R3-S10, 17.4R2-S12, 17.4R3-S4, 18.1R3-S12, 18.2R2-S8, 18.2R3-S6, 18.3R3-S4, 18.4R1-S8, 18.4R2-S6, 18.4R3-S6, 19.1R2-S2, 19.1R3-S3, 19.2R3-S1, 19.3R2-S5, 19.3R3-S1, 19.4R1-S3, 19.4R2-S3, 19.4R3, 20.1R2, 20.2R1-S3, 20.2R2, 20.3R1-S1, 20.3R2, 20.4R1, and all subsequent releases. Junos OS Evolved: 20.3R1-S1-EVO, 20.3R2-EVO, 20.4R1-EVO, and all subsequent releases.

workarounds

There are no viable workarounds for this issue.

ProductVulnerable rangeFixed versionAdvisory
Juniper Networks Junos OS>=15.1<15.1R7-S815.1R7-S8advisory ↗
Juniper Networks Junos OS>=15.1X49<15.1X490-D24015.1X490-D240advisory ↗
Juniper Networks Junos OS>=17.3<17.3R3-S1017.3R3-S10advisory ↗
Juniper Networks Junos OS>=17.4<17.4R2-S12, 17.4R3-S417.4R2-S12, 17.4R3-S4advisory ↗
Juniper Networks Junos OS>=18.1<18.1R3-S1218.1R3-S12advisory ↗
Juniper Networks Junos OS>=18.2<18.2R2-S8, 18.2R3-S618.2R2-S8, 18.2R3-S6advisory ↗
Juniper Networks Junos OS>=18.3<18.3R3-S418.3R3-S4advisory ↗
Juniper Networks Junos OS>=18.4<18.4R1-S8, 18.4R2-S6, 18.4R3-S618.4R1-S8, 18.4R2-S6, 18.4R3-S6advisory ↗
Juniper Networks Junos OS>=19.1<19.1R1-S6, 19.1R2-S2, 19.1R3-S319.1R1-S6, 19.1R2-S2, 19.1R3-S3advisory ↗
Juniper Networks Junos OS>=19.2<19.2R3-S119.2R3-S1advisory ↗
Juniper Networks Junos OS>=19.3<19.3R2-S5, 19.3R3-S119.3R2-S5, 19.3R3-S1advisory ↗
Juniper Networks Junos OS>=19.4<19.4R1-S3, 19.4R2-S3, 19.4R319.4R1-S3, 19.4R2-S3, 19.4R3advisory ↗
Juniper Networks Junos OS>=20.1<20.1R220.1R2advisory ↗
Juniper Networks Junos OS>=20.2<20.2R1-S3 20.2R220.2R1-S3 20.2R2advisory ↗
Juniper Networks Junos OS>=20.3<20.3R1-S1, 20.3R220.3R1-S1, 20.3R2advisory ↗
Juniper Networks Junos OS Evolved>=unspecified<20.3R1-S1-EVO, 20.3R2-EVO20.3R1-S1-EVO, 20.3R2-EVOadvisory ↗

References

cvedb.io · NVD · CISA KEV · FIRST EPSS · vendor advisories (CVE Program List v5). Informational only, no warranty — verify every remediation against the vendor advisory before acting on it. This product uses data from the NVD API but is not endorsed or certified by the NVD, CISA, FIRST.org or any vendor named. CVE® is a registered trademark of The MITRE Corporation.