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Fencer Intel
high 7.5

CVE-2021-0250 json

Junos OS and Junos OS Evolved: An attacker sending a specific crafted BGP update message will crash RPD

published 5y ago modified 4mo ago also EUVD-2021-2869

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.0%
EPSS 1.0% chance of exploitation in 30 days, percentile 63%
public exploits
0
none known

Summary

In segment routing traffic engineering (SRTE) environments where the BGP Monitoring Protocol (BMP) feature is enable, a vulnerability in the Routing Protocol Daemon (RPD) process of Juniper Networks Junos OS allows an attacker to send a specific crafted BGP update message causing the RPD service to core, creating a Denial of Service (DoS) Condition. Continued receipt and processing of this update message will create a sustained Denial of Service (DoS) condition. This issue affects IPv4 and IPv6 environments. This issue affects: Juniper Networks Junos OS 17.4 versions 17.4R1 and above prior to 17.4R2-S6, 17.4R3; 18.1 versions prior to 18.1R3-S7; 18.2 versions prior to 18.2R2-S6, 18.2R3-S3; 18.3 versions prior to 18.3R1-S7, 18.3R2-S3, 18.3R3; 18.4 versions prior to 18.4R1-S5, 18.4R2-S3, 18.4R3; 19.1 versions prior to 19.1R1-S4, 19.1R2; 19.2 versions prior to 19.2R1-S3, 19.2R2, This issue does not affect Junos OS releases prior to 17.4R1. This issue affects: Juniper Networks Junos OS Evolved 19.2-EVO versions prior to 19.2R2-EVO.

Patch / fix

  • Juniper Networks Junos OS 17.4R2-S6, 17.4R3, 18.1R3-S7, 18.2R2-S6, 18.2R3-S3, 18.3R1-S7, 18.3R2-S3, 18.3R3, 18.4R1-S5, 18.4R2-S3, 18.4R3, 19.1R1-S4, 19.1R2, 19.2R1-S3, 19.2R2
  • Juniper Networks Junos OS Evolved 19.2R2-EVO

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Exploit prediction

1.02% chance of exploitation in the next 30 days, higher than 63% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD 2.0 5.0 AV:N/AC:L/Au:N/C:N/I:N/A:P

Affected products

  • Juniper Networks Junos OS
  • Juniper Networks Junos OS Evolved

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.