Junos OS and Junos OS Evolved: A vulnerability in JDHCPD allows an attacker to send crafted IPv6 packets and arbitrarily execute commands on the target device.

published 2020-01-15 6 y ago modified 2026-06-17 4 mo ago also EUVD-2020-12479

cvss: 8.8; version 3.1, CNA
cisa kev: Not listed; not in CISA's catalog
epss: 0.9%; EPSS 0.9% chance of exploitation in 30 days, percentile 61%
public exploits: 0; none known

When a device using Juniper Network's Dynamic Host Configuration Protocol Daemon (JDHCPD) process on Junos OS or Junos OS Evolved which is configured in relay mode it vulnerable to an attacker sending crafted IPv6 packets who may then arbitrarily execute commands as root on the target device. This issue affects IPv6 JDHCPD services. This issue affects: Juniper Networks Junos OS: 15.1 versions prior to 15.1R7-S6; 15.1X49 versions prior to 15.1X49-D200; 15.1X53 versions prior to 15.1X53-D592; 16.1 versions prior to 16.1R7-S6; 16.2 versions prior to 16.2R2-S11; 17.1 versions prior to 17.1R2-S11, 17.1R3-S1; 17.2 versions prior to 17.2R2-S8, 17.2R3-S3; 17.3 versions prior to 17.3R3-S6; 17.4 versions prior to 17.4R2-S7, 17.4R3; 18.1 versions prior to 18.1R3-S8; 18.2 versions prior to 18.2R3-S2; 18.2X75 versions prior to 18.2X75-D60; 18.3 versions prior to 18.3R1-S6, 18.3R2-S2, 18.3R3; 18.4 versions prior to 18.4R1-S5, 18.4R2-S3, 18.4R3; 19.1 versions prior to 19.1R1-S3, 19.1R2; 19.2 versions prior to 19.2R1-S3, 19.2R2*. and All versions prior to 19.3R1 on Junos OS Evolved. This issue do not affect versions of Junos OS prior to 15.1, or JDHCPD operating as a local server in non-relay mode.

Patch / fix

fixed in 2

Juniper Networks Junos OS 15.1R7-S6, 15.1X49-D200, 15.1X53-D592, 16.1R7-S6, 16.2R2-S11, 17.1R2-S11, 17.1R3-S1, 17.2R2-S8, 17.2R3-S3, 17.3R3-S6, 17.4R2-S7, 17.4R3, 18.1R3-S8, 18.2R3-S2, 18.2X75-D60, 18.3R1-S6, 18.3R2-S2, 18.3R3, 18.4R1-S5, 18.4R2-S3, 18.4R3, 19.1R1-S3, 19.1R2, 19.2R1-S3, 19.2R2, 19.3R1, 19.3R2
Juniper Networks Junos OS Evolved 19.3R1

Exploit prediction

0.94% chance of exploitation in the next 30 days, higher than 61% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by	version	score	vector
CNA	3.1	8.8	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	3.1	8.8	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	8.3	AV:A/AC:L/Au:N/C:C/I:C/A:C

Affected products

Juniper Networks Junos OS
Juniper Networks Junos OS Evolved

Classification

Weakness

CWE-121 Stack-based Buffer Overflow
CWE-78 Improper Neutralization of Special Elements used in an OS Command

References

kb.juniper.net /JSA10981
vendor-advisory
prsearch.juniper.net /InfoCenter/index?page=prcontent&id=PR1449353
permissions-required

Sources

CVE List CVE-2020-1609
NVD CVE-2020-1609

Fencer Vulns 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.

Summary