USN-3586-2: DHCP vulnerabilities

Releases

• Ubuntu 12.04

Packages

• isc-dhcp - DHCP server and client

Details

USN-3586-1 fixed a vulnerability in DHCP. This update provides
the corresponding update for Ubuntu 12.04 ESM.

Original advisory details:

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 12.04

• isc-dhcp-server - 4.1.ESV-R4-0ubuntu5.13
• isc-dhcp-relay - 4.1.ESV-R4-0ubuntu5.13
• isc-dhcp-client - 4.1.ESV-R4-0ubuntu5.13
• isc-dhcp-server-ldap - 4.1.ESV-R4-0ubuntu5.13

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

References

• CVE-2018-5732
• CVE-2018-5733

Related notices

• USN-3586-1: isc-dhcp-client, isc-dhcp-client-udeb, isc-dhcp-server, isc-dhcp-relay, isc-dhcp-dev, isc-dhcp-server-ldap, isc-dhcp, isc-dhcp-common, isc-dhcp-client-ddns, isc-dhcp-client-noddns