An invalid hostname option can trigger an assertion failure in the Kea DHCPv4 server process (kea-dhcp4), causing the server process to exit. Versions affected: 1.4.0 to 1.5.0, 1.6.0-beta1, and 1.6.0-beta2.

The remote Ubuntu 16.04 LTS / 18.04 LTS host has packages installed that are affected by a vulnerability as referenced in the USN-7759-1 advisory.

    It was discovered that Kea DHCP did not correctly handle invalid hostnames. A remote attacker could     possibly use this issue to cause a denial of service.

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

There are packages installed that are affected by multiple vulnerabilities referenced in the following CVEs:

  - A packet containing a malformed DUID can cause the Kea DHCPv6 server process (kea-dhcp6) to exit due to an
    assertion failure. Versions affected: 1.4.0 to 1.5.0, 1.6.0-beta1, and 1.6.0-beta2. (CVE-2019-6472)

  - An invalid hostname option can trigger an assertion failure in the Kea DHCPv4 server process (kea-dhcp4),
    causing the server process to exit. Versions affected: 1.4.0 to 1.5.0, 1.6.0-beta1, and 1.6.0-beta2.
    (CVE-2019-6473)

  - A missing check on incoming client requests can be exploited to cause a situation where the Kea server's
    lease storage contains leases which are rejected as invalid when the server tries to load leases from
    storage on restart. If the number of such leases exceeds a hard-coded limit in the Kea code, a server
    trying to restart will conclude that there is a problem with its lease store and give up. Versions
    affected: 1.4.0 to 1.5.0, 1.6.0-beta1, and 1.6.0-beta2 (CVE-2019-6474)

Internet Systems Consortium, Inc. reports :

A packet containing a malformed DUID can cause the kea-dhcp6 server to terminate (CVE-2019-6472) [Medium]

An invalid hostname option can cause the kea-dhcp4 server to terminate (CVE-2019-6473) [Medium]

An oversight when validating incoming client requests can lead to a situation where the Kea server will exit when trying to restart (CVE-2019-6474) [Medium]

Fixes for CVE-2019-6472, CVE-2019-6473 and CVE-2019-6474

Note that Tenable Network Security has extracted the preceding description block directly from the Fedora update system website.
Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

ID	Name	Product	Family	Type	Severity
265734	Ubuntu 16.04 LTS / 18.04 LTS : Kea DHCP vulnerabilities (USN-7759-1)	Nessus	Ubuntu Local Security Checks	Local	medium
423992	Alpine: multiple kea packages: security update to 1.7.2-r0	Tenable Cloud Security	Alpine Linux Local Security Checks	Local	medium
423992	Alpine: multiple kea packages: security update to 1.7.2-r0	Tenable Self-Hosted Container Security	Alpine Linux Local Security Checks	Local	medium
129114	FreeBSD : ISC KEA -- Multiple vulnerabilities (20b92374-d62a-11e9-af73-001b217e4ee5)	Nessus	FreeBSD Local Security Checks	Local	medium
128561	Fedora 30 : kea (2019-0811a88d77)	Nessus	Fedora Local Security Checks	Local	medium

Detections

Analytics

CVE-2019-6473

medium

Tenable Plugins

medium

medium

medium

medium

medium