kbrain

CVE-2021-0211

CRITICAL · CVSS 10.0EPSS 1.3%EU EUVD

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.

Key facts

CVSS score
10.0 (v3.1)
Severity
CRITICAL
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:H
Weakness (CWE)
CWE-754
EPSS score
1.3% (71th percentile)
In CISA KEV
No
In EU EUVD
Yes (EUVD-2021-2830)
Published
January 15, 2021
NVD last modified
June 17, 2026
Status
Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2021-2830 in the EU Vulnerability Database. Last updated in EUVD on September 16, 2024.

View on the EU Vulnerability Database

Affected products

  • juniper / ex rps
  • juniper / ex2200
  • juniper / ex2200-c
  • juniper / ex2200-vc
  • juniper / ex2300
  • juniper / ex2300-c
  • juniper / ex2300m
  • juniper / ex3200
  • juniper / ex3300
  • juniper / ex3300-vc
  • juniper / ex3400
  • juniper / ex4200
  • juniper / ex4200-vc
  • juniper / ex4300
  • juniper / ex4300-24p
  • juniper / ex4300-24p-s
  • juniper / ex4300-24t
  • juniper / ex4300-24t-s
  • juniper / ex4300-32f
  • juniper / ex4300-32f-dc
  • juniper / ex4300-32f-s
  • juniper / ex4300-48mp
  • juniper / ex4300-48mp-s
  • juniper / ex4300-48p
  • juniper / ex4300-48p-s
  • juniper / ex4300-48t
  • juniper / ex4300-48t-afi
  • juniper / ex4300-48t-dc
  • juniper / ex4300-48t-dc-afi
  • juniper / ex4300-48t-s
  • juniper / ex4300-48tafi
  • juniper / ex4300-48tdc
  • juniper / ex4300-48tdc-afi
  • juniper / ex4300-mp
  • juniper / ex4300-vc
  • juniper / ex4300m
  • juniper / ex4400
  • juniper / ex4500
  • juniper / ex4500-vc
  • juniper / ex4550
  • juniper / ex4550-vc
  • juniper / ex4550/vc
  • juniper / ex4600
  • juniper / ex4600-vc
  • juniper / ex4650
  • juniper / ex6200
  • juniper / ex6210
  • juniper / ex8200
  • juniper / ex8200-vc
  • juniper / ex8208

and 286 more…

Certified products that may be affected

1 FIPS 140 or Common Criteria certified product, from automated matching by sec-certs.org.

References

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

Query CVEs from your AI assistant

The CVE/NVD Explorer brain answers CVE questions directly inside Claude, ChatGPT, or any MCP assistant — always up to date, no setup. Add it once and stop pasting advisories into chat.

Add the CVE brain