CVE-2021-31374

HighCVSS 7.5/10Last modified Jun 17, 2026

Description

On Juniper Networks Junos OS and Junos OS Evolved devices processing a specially crafted BGP UPDATE or KEEPALIVE message can lead to a routing process daemon (RPD) crash and restart, causing a Denial of Service (DoS). Continued receipt and processing of this message will create a sustained Denial of Service (DoS) condition. This issue affects both IBGP and EBGP deployments over IPv4 or IPv6. This issue affects: Juniper Networks Junos OS: 17.3 versions prior to 17.3R3-S11; 17.4 versions prior to 17.4R2-S13, 17.4R3-S4; 18.1 versions prior to 18.1R3-S12; 18.2 versions prior to 18.2R2-S8, 18.2R3-S7; 18.3 versions prior to 18.3R3-S4; 18.4 versions prior to 18.4R1-S8, 18.4R2-S7, 18.4R3-S7; 19.1 versions prior to 19.1R1-S6, 19.1R2-S2, 19.1R3-S4; 19.2 versions prior to 19.2R1-S6, 19.2R3-S1; 19.3 versions prior to 19.3R2-S5, 19.3R3-S1; 19.4 versions prior to 19.4R1-S4, 19.4R1-S4, 19.4R2-S3, 19.4R3-S1; 20.1 versions prior to 20.1R2; 20.2 versions prior to 20.2R2; 20.3 versions prior to 20.3R1-S1, 20.3R2. Juniper Networks Junos OS Evolved: 20.3 versions prior to 20.3R2-EVO.

Metrics

CVSS 3.1 7.5/10CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Weakness enumeration

CWE-787

Affected software

VendorProductVersions
Juniper NetworksJunos OS>= 17.3, < 17.3R3-S11; >= 17.4, < 17.4R2-S13, 17.4R3-S4; >= 18.1, < 18.1R3-S12; >= 18.2, < 18.2R2-S8, 18.2R3-S7; >= 18.3, < 18.3R3-S4; >= 18.4, < 18.4R1-S8, 18.4R2-S7, 18.4R3-S7; >= 19.1, < 19.1R1-S6, 19.1R2-S2, 19.1R3-S4; >= 19.2, < 19.2R1-S6, 19.2R3-S1; >= 19.3, < 19.3R2-S5, 19.3R3-S1; >= 19.4, < 19.4R1-S4, 19.4R2-S3, 19.4R3-S1; >= 20.1, < 20.1R2; >= 20.2, < 20.2R2; >= 20.3, < 20.3R1-S1, 20.3R2
Juniper NetworksJunos OS Evolved>= 20.3, < 20.3R2-EVO

References

Timeline

Published
Oct 19, 2021
Last modified
Jun 17, 2026
NVD status
Modified

Related CVEs from 2021

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CVE-2021-31374: High severity, CVSS 7.5 | Vulnix