|| ||Pat Riehecky <firstname.lastname@example.org> |
|| ||Security ERRATA Moderate: dnsmasq on SL6.x i386/x86_64 |
|| ||Thu, 28 Feb 2013 16:16:31 -0600|
|| ||Article, Thread
Synopsis: Moderate: dnsmasq security, bug fix and enhancement
Issue Date: 2013-02-21
CVE Numbers: CVE-2012-3411
It was discovered that dnsmasq, when used in combination with certain
configurations, could incorrectly process network packets from network
interfaces that were intended to be prohibited. A remote, unauthenticated
attacker could exploit this flaw to cause a denial of service via DNS
amplification attacks. (CVE-2012-3411)
In order to fully address this issue, libvirt package users are advised
to install updated libvirt packages.
This update also fixes the following bug:
* Due to a regression, the lease change script was disabled.
"dhcp-script" option in the /etc/dnsmasq.conf configuration file did not
This update corrects the problem and the "dhcp-script" option now works as
This update also adds the following enhancements:
* Prior to this update, dnsmasq did not validate that the tftp directory
actually existed and was a directory. Consequently, configuration errors
not immediately reported on startup. This update improves the code to
the tftp root directory option. As a result, fault finding is simplified
especially when dnsmasq is called by external processes such as libvirt.
* The dnsmasq init script used an incorrect Process Identifier (PID) in the
"stop", "restart", and "condrestart" commands. Consequently, if there
dnsmasq instances running besides the system one started by the init script,
then repeated calling of "service dnsmasq" with "stop" or "restart"
all running dnsmasq instances, including ones not started with the init
The dnsmasq init script code has been corrected to obtain the correct
calling the "stop", "restart", and "condrestart" commands. As a result, if
there are dnsmasq instances running in addition to the system one started by
the init script, then by calling "service dnsmasq" with "stop" or "restart"
only the system one is stopped or restarted.
* When two or more dnsmasq processes were running with DHCP enabled on one
interface, DHCP RELEASE packets were sometimes lost. Consequently, when
more dnsmasq processes were running with DHCP enabled on one interface,
releasing IP addresses sometimes failed. This update sets the
socket option on DHCP sockets if running dnsmasq with DHCP enabled on one
interface. As a result, when two or more dnsmasq processes are running with
DHCP enabled on one interface, they can release IP addresses as expected.
- Scientific Linux Development Team
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