ESB-2018.0605 - [Ubuntu] isc-dhcp-client: Multiple vulnerabilities 2018-03-02

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             AUSCERT External Security Bulletin Redistribution

                           DHCP vulnerabilities
                               2 March 2018


        AusCERT Security Bulletin Summary

Product:           isc-dhcp-client
Publisher:         Ubuntu
Operating System:  Ubuntu
Impact/Access:     Execute Arbitrary Code/Commands -- Remote/Unauthenticated
                   Denial of Service               -- Remote/Unauthenticated
Resolution:        Patch/Upgrade
CVE Names:         CVE-2018-5733 CVE-2018-5732 CVE-2017-3144

Reference:         ASB-2017.0219

Original Bulletin:

- --------------------------BEGIN INCLUDED TEXT--------------------

Ubuntu Security Notice USN-3586-1
March 01, 2018

isc-dhcp vulnerabilities

A security issue affects these releases of Ubuntu and its derivatives:

- - Ubuntu 17.10
- - Ubuntu 16.04 LTS
- - Ubuntu 14.04 LTS


Several security issues were fixed in DHCP.

Software Description:
- - isc-dhcp: DHCP server and client


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:
  isc-dhcp-client                 4.3.5-3ubuntu2.2
  isc-dhcp-relay                  4.3.5-3ubuntu2.2
  isc-dhcp-server                 4.3.5-3ubuntu2.2
  isc-dhcp-server-ldap            4.3.5-3ubuntu2.2

Ubuntu 16.04 LTS:
  isc-dhcp-client                 4.3.3-5ubuntu12.9
  isc-dhcp-relay                  4.3.3-5ubuntu12.9
  isc-dhcp-server                 4.3.3-5ubuntu12.9
  isc-dhcp-server-ldap            4.3.3-5ubuntu12.9

Ubuntu 14.04 LTS:
  isc-dhcp-client                 4.2.4-7ubuntu12.12
  isc-dhcp-relay                  4.2.4-7ubuntu12.12
  isc-dhcp-server                 4.2.4-7ubuntu12.12
  isc-dhcp-server-ldap            4.2.4-7ubuntu12.12

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

  CVE-2016-2774, CVE-2017-3144, CVE-2018-5732, CVE-2018-5733

Package Information:

- --------------------------END INCLUDED TEXT--------------------

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