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2019-04 Security Bulletin: Junos OS: jdhcpd daemon memory consumption Denial of Service when receiving specific IPv6 DHCP packets. (CVE-2019-0031)

  [JSA10920] Show Article Properties

Product Affected:
This issue affects Junos OS 17.4, 18.1.

Specific IPv6 DHCP packets received by the jdhcpd daemon will cause a memory resource consumption issue to occur on a Junos OS device using the jdhcpd daemon configured to respond to IPv6 requests. Once started, memory consumption will eventually impact any IPv4 or IPv6 request serviced by the jdhcpd daemon, thus creating a Denial of Service (DoS) condition to clients requesting and not receiving IP addresses. Additionally, some clients which were previously holding IPv6 addresses will not have their IPv6 Identity Association (IA) address and network tables agreed upon by the jdhcpd daemon after the failover event occurs, which leads to more than one interface, and multiple IP addresses, being denied on the client.

Affected releases are Juniper Networks Junos OS:

  • 17.4 versions prior to 17.4R2;
  • 18.1 versions prior to 18.1R2.

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

This issue was found during internal product security testing or research.

This issue has been assigned CVE-2019-0031.


The following software releases have been updated to resolve this specific issue: 17.4R2, 18.1R2, 18.2R1, and all subsequent releases.

This issue is being tracked as PR 1333381 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).


Customers may discontinue processing or serving DHCPv6 address assignments until such time that fixes can be taken.  
This workaround is helpful for large IPv4 environments with fewer or considered less important IPv6 clients.

Software Releases, patches and updates are available at
Modification History:
2019-04-10: Initial Publication. 
Related Links:
CVSS Score:
7.4 (CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H)
Risk Level:
Risk Assessment:
Information for how Juniper Networks uses CVSS can be found at KB 16446 "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."