CVE detail

CVE-2021-0234 — CVE-2021-0234

Published 2021-04-22 · Modified 2026-06-17 · Vendor juniper · Product junos · Source nvd
MEDIUM
severity
CVSS-derived band
5.8
CVSS v3
0–10 scale
0.0095
EPSS probability
exploitation probability, 30d
58.0%
EPSS percentile
percentile vs all CVEs
NOT LISTED
CISA KEV
known exploited catalog

Description

Due to an improper Initialization vulnerability on Juniper Networks Junos OS QFX5100-96S devices with QFX 5e Series image installed, ddos-protection configuration changes will not take effect beyond the default DDoS (Distributed Denial of Service) settings when configured from the CLI. The DDoS protection (jddosd) daemon allows the device to continue to function while protecting the packet forwarding engine (PFE) during the DDoS attack. When this issue occurs, the default DDoS settings within the PFE apply, as CPU bound packets will be throttled and dropped in the PFE when the limits are exceeded. To check if the device has this issue, the administrator can execute the following command to monitor the status of DDoS protection: user@device> show ddos-protection protocols error: the ddos-pr

Remediation

vendor remediation guidance

The following software releases have been updated to resolve this specific issue: 17.3R3-S10, 17.4R3-S4, 18.1R3-S10, 18.2R3-S3, 18.3R3-S2, 18.4R2-S4, 18.4R3-S1, 19.1R3, 19.1R3-S4, 19.2R2, 19.3R3, 19.4R2, 20.1R1, and all subsequent releases.

workarounds

The following command can be used to enable ddos-protection manually: root@device% /usr/sbin/jddosd -N &

ProductVulnerable rangeFixed versionAdvisory
Juniper Networks Junos OS>=17.3<17.3R3-S1017.3R3-S10advisory ↗
Juniper Networks Junos OS>=17.4<17.4R3-S417.4R3-S4advisory ↗
Juniper Networks Junos OS>=18.1<18.1R3-S1018.1R3-S10advisory ↗
Juniper Networks Junos OS>=18.2<18.2R3-S318.2R3-S3advisory ↗
Juniper Networks Junos OS>=18.3<18.3R3-S218.3R3-S2advisory ↗
Juniper Networks Junos OS>=18.4<18.4R2-S4, 18.4R3-S118.4R2-S4, 18.4R3-S1advisory ↗
Juniper Networks Junos OS>=19.1<19.1R3, 19.1R3-S419.1R3, 19.1R3-S4advisory ↗
Juniper Networks Junos OS>=19.2<19.2R219.2R2advisory ↗
Juniper Networks Junos OS>=19.3<19.3R319.3R3advisory ↗
Juniper Networks Junos OS>=19.4<19.4R219.4R2advisory ↗

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.