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

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 1.7% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2019-04-10 · updated 2026-06-17
Weakness: CWE-400

Description

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.

Affected products

Juniper Junos OS: from 17.4 before 17.4r2; from 18.1 before 18.1r2 — fixed in 17.4r2, 18.1r2

How to fix

Upgrade to a fixed version: Juniper Junos OS 17.4r2, 18.1r2. Check the vendor advisory for mitigations.

References

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