CVE detail

CVE-2021-0240 — CVE-2021-0240

Published 2021-04-22 · Modified 2026-06-17 · Vendor juniper · Product junos · Source nvd
HIGH
severity
CVSS-derived band
7.4
CVSS v3
0–10 scale
0.0040
EPSS probability
exploitation probability, 30d
33.0%
EPSS percentile
percentile vs all CVEs
NOT LISTED
CISA KEV
known exploited catalog

Description

On Juniper Networks Junos OS platforms configured as DHCPv6 local server or DHCPv6 Relay Agent, the Juniper Networks Dynamic Host Configuration Protocol Daemon (JDHCPD) process might crash if a malformed DHCPv6 packet is received, resulting in a restart of the daemon. The daemon automatically restarts without intervention, but continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition. This issue only affects DHCPv6. DHCPv4 is not affected by this issue. This issue affects Juniper Networks Junos OS: 17.3 versions prior to 17.3R3-S12; 17.4 versions prior to 17.4R3-S5; 18.1 versions prior to 18.1R3-S13; 18.2 versions prior to 18.2R3-S8; 18.3 versions prior to 18.3R3-S5; 18.4 versions prior to 18.4R1-S8, 18.4R3-S7; 19.1 versions prior to 19.1R3-S

Remediation

vendor remediation guidance

The following software releases have been updated to resolve this specific issue: Junos OS 17.3R3-S12, 17.4R3-S5, 18.1R3-S13, 18.2R3-S8, 18.3R3-S5, 18.4R1-S8, 18.4R3-S7, 19.1R3-S5, 19.2R3-S2, 19.3R3-S2, 19.4R3-S2, 20.1R3, 20.2R2-S3, 20.2R3, 20.3R2, 20.4R2, 21.1R1, and all subsequent releases.

workarounds

There are no viable workarounds for this issue.

ProductVulnerable rangeFixed versionAdvisory
Juniper Networks Junos OS>=17.3<17.3R3-S1217.3R3-S12advisory ↗
Juniper Networks Junos OS>=17.4<17.4R3-S517.4R3-S5advisory ↗
Juniper Networks Junos OS>=18.1<18.1R3-S1318.1R3-S13advisory ↗
Juniper Networks Junos OS>=18.2<18.2R3-S818.2R3-S8advisory ↗
Juniper Networks Junos OS>=18.3<18.3R3-S518.3R3-S5advisory ↗
Juniper Networks Junos OS>=18.4<18.4R1-S8, 18.4R3-S718.4R1-S8, 18.4R3-S7advisory ↗
Juniper Networks Junos OS>=19.1<19.1R3-S519.1R3-S5advisory ↗
Juniper Networks Junos OS>=19.2<19.2R3-S219.2R3-S2advisory ↗
Juniper Networks Junos OS>=19.3<19.3R3-S219.3R3-S2advisory ↗
Juniper Networks Junos OS>=19.4<19.4R3-S219.4R3-S2advisory ↗
Juniper Networks Junos OS>=20.1<20.1R320.1R3advisory ↗
Juniper Networks Junos OS>=20.2<20.2R2-S3, 20.2R320.2R2-S3, 20.2R3advisory ↗
Juniper Networks Junos OS>=20.3<20.3R220.3R2advisory ↗
Juniper Networks Junos OS>=20.4<20.4R220.4R2advisory ↗

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.