CVE-2019-0063: When an MX Series Broadband Remote Access Server (BRAS) is configured as a Broadband Network Gateway (BNG) with DHCPv6 enabled, jdhcpd might crash whe...

Description

When an MX Series Broadband Remote Access Server (BRAS) is configured as a Broadband Network Gateway (BNG) with DHCPv6 enabled, jdhcpd might crash when receiving a specific crafted DHCP response message on a subscriber interface. The daemon automatically restarts without intervention, but continuous receipt of specific crafted DHCP messages will repeatedly crash jdhcpd, leading to an extended Denial of Service (DoS) condition. This issue only affects systems configured with DHCPv6 enabled. DHCPv4 is unaffected by this issue. This issue affects Juniper Networks Junos OS: 15.1 versions prior to 15.1R7-S5 on MX Series; 16.1 versions prior to 16.1R7-S5 on MX Series; 16.2 versions prior to 16.2R2-S10 on MX Series; 17.1 versions prior to 17.1R3-S1 on MX Series; 17.2 versions prior to 17.2R3-S2 on MX Series; 17.3 versions prior to 17.3R3-S6 on MX Series; 17.4 versions prior to 17.4R2-S5, 17.4R3 on MX Series; 18.1 versions prior to 18.1R3-S6 on MX Series; 18.2 versions prior to 18.2R2-S4, 18.2R3 on MX Series; 18.2X75 versions prior to 18.2X75-D50 on MX Series; 18.3 versions prior to 18.3R1-S5, 18.3R3 on MX Series; 18.4 versions prior to 18.4R2 on MX Series; 19.1 versions prior to 19.1R1-S2, 19.1R2 on MX Series.

Metrics

CVSS 3.1

7.5/10

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

EPSS Probability

1.28%

66.4th percentile

Probability of exploitation in the next 30 days. Learn more

Affected Software

Vendor	Product	Versions	Update
Juniper	Junos	15.1	A1
Juniper	Junos	16.1	—
Juniper	Junos	16.2	—
Juniper	Junos	17.1	—
Juniper	Junos	17.2	—
Juniper	Junos	17.3	—
Juniper	Junos	17.4	—
Juniper	Junos	18.1	—
Juniper	Junos	18.2	—
Juniper	Junos	18.2x75	—
Juniper	Junos	18.3	—
Juniper	Junos	18.4	—
Juniper	Junos	19.1	—

References

https://kb.juniper.net/JSA10962Vendor Advisory
https://kb.juniper.net/JSA10962Vendor Advisory

Timeline

Published: Oct 9, 2019
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2019-0063?

When an MX Series Broadband Remote Access Server (BRAS) is configured as a Broadband Network Gateway (BNG) with DHCPv6 enabled, jdhcpd might crash when receiving a specific crafted DHCP response message on a subscriber interface. The daemon automatically restarts without intervention, but continuous receipt of specific crafted DHCP messages will repeatedly crash jdhcpd, leading to an extended Denial of Service (DoS) condition. This issue only affects systems configured with DHCPv6 enabled. DHCPv4 is unaffected by this issue. This issue affects Juniper Networks Junos OS: 15.1 versions prior to 15.1R7-S5 on MX Series; 16.1 versions prior to 16.1R7-S5 on MX Series; 16.2 versions prior to 16.2R2-S10 on MX Series; 17.1 versions prior to 17.1R3-S1 on MX Series; 17.2 versions prior to 17.2R3-S2 on MX Series; 17.3 versions prior to 17.3R3-S6 on MX Series; 17.4 versions prior to 17.4R2-S5, 17.4R3 on MX Series; 18.1 versions prior to 18.1R3-S6 on MX Series; 18.2 versions prior to 18.2R2-S4, 18.2R3 on MX Series; 18.2X75 versions prior to 18.2X75-D50 on MX Series; 18.3 versions prior to 18.3R1-S5, 18.3R3 on MX Series; 18.4 versions prior to 18.4R2 on MX Series; 19.1 versions prior to 19.1R1-S2, 19.1R2 on MX Series.

How severe is CVE-2019-0063?

CVE-2019-0063 has a CVSS score of 7.5/10 (HIGH severity). The EPSS model estimates a 1.28% probability of exploitation in the next 30 days.

How do I fix CVE-2019-0063?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.