====================================================================                   Red Hat Security Advisory

Synopsis:          Low: dhcp security and bug fix update
Advisory ID:       RHSA-2013:0504-02
Product:           Red Hat Enterprise Linux
Advisory URL:      https://access.redhat.com/errata/RHSA-2013:0504.html
Issue date:        2013-02-21
CVE Names:         CVE-2012-3955 
====================================================================
1. Summary:

Updated dhcp packages that fix one security issue and two bugs are now
available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having low
security impact. A Common Vulnerability Scoring System (CVSS) base score,
which gives a detailed severity rating, is available from the CVE link in
the References section.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Desktop (v. 6) - i386, x86_64
Red Hat Enterprise Linux Desktop Optional (v. 6) - i386, x86_64
Red Hat Enterprise Linux HPC Node (v. 6) - x86_64
Red Hat Enterprise Linux HPC Node Optional (v. 6) - x86_64
Red Hat Enterprise Linux Server (v. 6) - i386, ppc64, s390x, x86_64
Red Hat Enterprise Linux Server Optional (v. 6) - i386, ppc64, s390x, x86_64
Red Hat Enterprise Linux Workstation (v. 6) - i386, x86_64
Red Hat Enterprise Linux Workstation Optional (v. 6) - i386, x86_64

3. Description:

The dhcp packages provide the Dynamic Host Configuration Protocol (DHCP)
that allows individual devices on an IP network to get their own network
configuration information, including an IP address, a subnet mask, and a
broadcast address.

A flaw was found in the way the dhcpd daemon handled the expiration time of
IPv6 leases. If dhcpd's configuration was changed to reduce the default
IPv6 lease time, lease renewal requests for previously assigned leases
could cause dhcpd to crash. (CVE-2012-3955)

This update also fixes the following bugs:

* Prior to this update, the DHCP server discovered only the first IP
address of a network interface if the network interface had more than one
configured IP address. As a consequence, the DHCP server failed to
restart if the server was configured to serve only a subnet of the
following IP addresses. This update modifies network interface addresses
discovery code to find all addresses of a network interface. The DHCP
server can also serve subnets of other addresses. (BZ#803540)

* Prior to this update, the dhclient rewrote the /etc/resolv.conf file
with backup data after it was stopped even when the PEERDNS flag was set
to "no" before shut down if the configuration file was changed while the
dhclient ran with PEERDNS=yes. This update removes the backing up and
restoring functions for this configuration file from the dhclient-script.
Now, the dhclient no longer rewrites the /etc/resolv.conf file when
stopped. (BZ#824622)

All users of DHCP are advised to upgrade to these updated packages, which
fix these issues. After installing this update, all DHCP servers will be
restarted automatically.

4. Solution:

Before applying this update, make sure all previously-released errata
relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to
use the Red Hat Network to apply this update are available at
https://access.redhat.com/knowledge/articles/11258

5. Bugs fixed (http://bugzilla.redhat.com/):

803540 - DHCP server fails to start if the subnet is not the primary subnet for a device
824622 - dhclient-script should honor PEERDNS on quit
856766 - CVE-2012-3955 dhcp: reduced expiration time of an IPv6 lease may cause dhcpd to crash

6. Package List:

Red Hat Enterprise Linux Desktop (v. 6):

Source:

i386:
dhclient-4.1.1-34.P1.el6.i686.rpm
dhcp-common-4.1.1-34.P1.el6.i686.rpm
dhcp-debuginfo-4.1.1-34.P1.el6.i686.rpm

x86_64:
dhclient-4.1.1-34.P1.el6.x86_64.rpm
dhcp-common-4.1.1-34.P1.el6.x86_64.rpm
dhcp-debuginfo-4.1.1-34.P1.el6.x86_64.rpm

Red Hat Enterprise Linux Desktop Optional (v. 6):

Source:

i386:
dhcp-4.1.1-34.P1.el6.i686.rpm
dhcp-debuginfo-4.1.1-34.P1.el6.i686.rpm
dhcp-devel-4.1.1-34.P1.el6.i686.rpm

x86_64:
dhcp-4.1.1-34.P1.el6.x86_64.rpm
dhcp-debuginfo-4.1.1-34.P1.el6.i686.rpm
dhcp-debuginfo-4.1.1-34.P1.el6.x86_64.rpm
dhcp-devel-4.1.1-34.P1.el6.i686.rpm
dhcp-devel-4.1.1-34.P1.el6.x86_64.rpm

Red Hat Enterprise Linux HPC Node (v. 6):

Source:

x86_64:
dhclient-4.1.1-34.P1.el6.x86_64.rpm
dhcp-common-4.1.1-34.P1.el6.x86_64.rpm
dhcp-debuginfo-4.1.1-34.P1.el6.x86_64.rpm

Red Hat Enterprise Linux HPC Node Optional (v. 6):

Source:

x86_64:
dhcp-4.1.1-34.P1.el6.x86_64.rpm
dhcp-debuginfo-4.1.1-34.P1.el6.i686.rpm
dhcp-debuginfo-4.1.1-34.P1.el6.x86_64.rpm
dhcp-devel-4.1.1-34.P1.el6.i686.rpm
dhcp-devel-4.1.1-34.P1.el6.x86_64.rpm

Red Hat Enterprise Linux Server (v. 6):

Source:

i386:
dhclient-4.1.1-34.P1.el6.i686.rpm
dhcp-4.1.1-34.P1.el6.i686.rpm
dhcp-common-4.1.1-34.P1.el6.i686.rpm
dhcp-debuginfo-4.1.1-34.P1.el6.i686.rpm

ppc64:
dhclient-4.1.1-34.P1.el6.ppc64.rpm
dhcp-4.1.1-34.P1.el6.ppc64.rpm
dhcp-common-4.1.1-34.P1.el6.ppc64.rpm
dhcp-debuginfo-4.1.1-34.P1.el6.ppc64.rpm

s390x:
dhclient-4.1.1-34.P1.el6.s390x.rpm
dhcp-4.1.1-34.P1.el6.s390x.rpm
dhcp-common-4.1.1-34.P1.el6.s390x.rpm
dhcp-debuginfo-4.1.1-34.P1.el6.s390x.rpm

x86_64:
dhclient-4.1.1-34.P1.el6.x86_64.rpm
dhcp-4.1.1-34.P1.el6.x86_64.rpm
dhcp-common-4.1.1-34.P1.el6.x86_64.rpm
dhcp-debuginfo-4.1.1-34.P1.el6.x86_64.rpm

Red Hat Enterprise Linux Server Optional (v. 6):

Source:

i386:
dhcp-debuginfo-4.1.1-34.P1.el6.i686.rpm
dhcp-devel-4.1.1-34.P1.el6.i686.rpm

ppc64:
dhcp-debuginfo-4.1.1-34.P1.el6.ppc.rpm
dhcp-debuginfo-4.1.1-34.P1.el6.ppc64.rpm
dhcp-devel-4.1.1-34.P1.el6.ppc.rpm
dhcp-devel-4.1.1-34.P1.el6.ppc64.rpm

s390x:
dhcp-debuginfo-4.1.1-34.P1.el6.s390.rpm
dhcp-debuginfo-4.1.1-34.P1.el6.s390x.rpm
dhcp-devel-4.1.1-34.P1.el6.s390.rpm
dhcp-devel-4.1.1-34.P1.el6.s390x.rpm

x86_64:
dhcp-debuginfo-4.1.1-34.P1.el6.i686.rpm
dhcp-debuginfo-4.1.1-34.P1.el6.x86_64.rpm
dhcp-devel-4.1.1-34.P1.el6.i686.rpm
dhcp-devel-4.1.1-34.P1.el6.x86_64.rpm

Red Hat Enterprise Linux Workstation (v. 6):

Source:

i386:
dhclient-4.1.1-34.P1.el6.i686.rpm
dhcp-4.1.1-34.P1.el6.i686.rpm
dhcp-common-4.1.1-34.P1.el6.i686.rpm
dhcp-debuginfo-4.1.1-34.P1.el6.i686.rpm

x86_64:
dhclient-4.1.1-34.P1.el6.x86_64.rpm
dhcp-4.1.1-34.P1.el6.x86_64.rpm
dhcp-common-4.1.1-34.P1.el6.x86_64.rpm
dhcp-debuginfo-4.1.1-34.P1.el6.x86_64.rpm

Red Hat Enterprise Linux Workstation Optional (v. 6):

Source:

i386:
dhcp-debuginfo-4.1.1-34.P1.el6.i686.rpm
dhcp-devel-4.1.1-34.P1.el6.i686.rpm

x86_64:
dhcp-debuginfo-4.1.1-34.P1.el6.i686.rpm
dhcp-debuginfo-4.1.1-34.P1.el6.x86_64.rpm
dhcp-devel-4.1.1-34.P1.el6.i686.rpm
dhcp-devel-4.1.1-34.P1.el6.x86_64.rpm

These packages are GPG signed by Red Hat for security.  Our key and
details on how to verify the signature are available from
https://access.redhat.com/security/team/key/#package

7. References:

https://www.redhat.com/security/data/cve/CVE-2012-3955.html
https://access.redhat.com/security/updates/classification/#low

8. Contact:

The Red Hat security contact is .  More contact
details at https://access.redhat.com/security/team/contact/

Copyright 2013 Red Hat, Inc.