USN-3586-1: DHCP vulnerabilities

01 March 2018

Several security issues were fixed in DHCP.

Releases

Packages

  • isc-dhcp - DHCP server and client

Details

Konstantin Orekhov discovered that the DHCP server incorrectly handled a
large number of concurrent TCP sessions. A remote attacker could possibly
use this issue to cause a denial of service. This issue only affected
Ubuntu 14.04 LTS and Ubuntu 16.04 LTS. (CVE-2016-2774)

It was discovered that the DHCP server incorrectly handled socket
descriptors. A remote attacker could possibly use this issue to cause a
denial of service. (CVE-2017-3144)

Felix Wilhelm discovered that the DHCP client incorrectly handled certain
malformed responses. A remote attacker could use this issue to cause the
DHCP client to crash, resulting in a denial of service, or possibly execute
arbitrary code. In the default installation, attackers would be isolated by
the dhclient AppArmor profile. (CVE-2018-5732)

Felix Wilhelm discovered that the DHCP server incorrectly handled reference
counting. A remote attacker could possibly use this issue to cause the DHCP
server to crash, resulting in a denial of service. (CVE-2018-5733)

Update instructions

The problem can be corrected by updating your system to the following package versions:

Ubuntu 17.10
Ubuntu 16.04
Ubuntu 14.04

In general, a standard system update will make all the necessary changes.

Related notices

  • USN-3586-2: isc-dhcp-relay, isc-dhcp-server, isc-dhcp-client, isc-dhcp, isc-dhcp-server-ldap