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2019-10 Security Bulletin: Junos OS: MX Series: jdhcpd crash when receiving a specific crafted DHCP response message (CVE-2019-0063)



Article ID: JSA10962 SECURITY_ADVISORIES Last Updated: 09 Oct 2019Version: 3.0
Product Affected:
This issue affects Junos OS 15.1, 16.1, 16.2, 17.1, 17.2, 17.3, 17.4, 18.1, 18.2, 18.2X75, 18.3, 18.4, 19.1. Affected platforms: MX Series.

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.

Systems with DHCPv6 enabled will include a configuration similar to:

[edit system services]
dhcp-local-server {
   dhcpv6 {


Juniper SIRT is not aware of any malicious exploitation of this vulnerability.

This issue was seen during production usage.

This issue has been assigned CVE-2019-0063.


The following software releases have been updated to resolve this specific issue: 15.1R7-S5, 16.1R7-S5, 16.2R2-S10, 17.1R3-S1, 17.2R3-S2, 17.3R3-S6, 17.4R2-S5, 17.4R3, 18.1R3-S6, 18.2R2-S4, 18.2R3, 18.2X75-D50, 18.3R1-S5, 18.3R3, 18.4R2, 19.1R1-S2, 19.1R2, 19.2R1, and all subsequent releases.

This issue is being tracked as PR 1415242 which is visible on the Customer Support website.

Note: Juniper SIRT's policy is not to evaluate releases which are beyond End of Engineering (EOE) or End of Life (EOL).

There are no viable workarounds for this issue.
Software Releases, patches and updates are available at
Modification History:
2019-10-09: Initial Publication.
CVSS Score:
6.5 (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
Severity Level:
Severity Assessment:
Information for how Juniper Networks uses CVSS can be found at KB 16446 "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."

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