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Security Advisory Moderate: dnsmasq security, bug fix and enhancement update

Advisory: RHSA-2013:0277-2
Type: Security Advisory
Severity: Moderate
Issued on: 2013-02-21
Last updated on: 2013-02-21
Affected Products: Red Hat Enterprise Linux Desktop (v. 6)
Red Hat Enterprise Linux HPC Node (v. 6)
Red Hat Enterprise Linux Server (v. 6)
Red Hat Enterprise Linux Workstation (v. 6)
CVEs (cve.mitre.org): CVE-2012-3411

Details

Updated dnsmasq packages that fix one security issue, one bug, and add
various enhancements are now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having moderate
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.

The dnsmasq packages contain Dnsmasq, a lightweight DNS (Domain Name
Server) forwarder and DHCP (Dynamic Host Configuration Protocol) server.

It was discovered that dnsmasq, when used in combination with certain
libvirtd 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. Refer to RHSA-2013:0276 for additional
information.

This update also fixes the following bug:

* Due to a regression, the lease change script was disabled. Consequently,
the "dhcp-script" option in the /etc/dnsmasq.conf configuration file did
not work. This update corrects the problem and the "dhcp-script" option now
works as expected. (BZ#815819)

This update also adds the following enhancements:

* Prior to this update, dnsmasq did not validate that the tftp directory
given actually existed and was a directory. Consequently, configuration
errors were not immediately reported on startup. This update improves the
code to validate the tftp root directory option. As a result, fault finding
is simplified especially when dnsmasq is called by external processes such
as libvirt. (BZ#824214)

* The dnsmasq init script used an incorrect Process Identifier (PID) in the
"stop", "restart", and "condrestart" commands. Consequently, if there were
some dnsmasq instances running besides the system one started by the init
script, then repeated calling of "service dnsmasq" with "stop" or "restart"
would kill all running dnsmasq instances, including ones not started with
the init script. The dnsmasq init script code has been corrected to obtain
the correct PID when 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. (BZ#850944)

* When two or more dnsmasq processes were running with DHCP enabled on one
interface, DHCP RELEASE packets were sometimes lost. Consequently, when two
or more dnsmasq processes were running with DHCP enabled on one interface,
releasing IP addresses sometimes failed. This update sets the
SO_BINDTODEVICE 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. (BZ#887156)

All users of dnsmasq are advised to upgrade to these updated packages,
which fix these issues and add these enhancements.


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

Updated packages

Red Hat Enterprise Linux Desktop (v. 6)

SRPMS:
dnsmasq-2.48-13.el6.src.rpm     MD5: a5231f28d49afb08825e1f90ac6b84de
SHA-256: 76d7f65e8ec14e1fea6a0d0b69cb4dcb13ce1e28ac312a62850360e34a187d0d
 
IA-32:
dnsmasq-2.48-13.el6.i686.rpm     MD5: ea20d0d6731b747d1cddb801df7c53db
SHA-256: bb285fe2631f788cb972a375fc6bd6bad55a865511b674a09611519e548a1f04
dnsmasq-debuginfo-2.48-13.el6.i686.rpm     MD5: d68b02afce84559c9b48dbfecf954d7b
SHA-256: 090a9e0e0fb03e96335a227839c16cebf875c809204986d07883994c029a85b6
dnsmasq-utils-2.48-13.el6.i686.rpm     MD5: 52d796d3d8bc39852e1d11667240e4c2
SHA-256: f14838f3a69a9797859e2f9698681c92e6811ef3e6bcc5b46aa83359857c02b5
 
x86_64:
dnsmasq-2.48-13.el6.x86_64.rpm     MD5: 593c4c51e3ac44528853afe36d8fd879
SHA-256: 31e8dd6523f064fe394b2a47a39525276275c22d7978d2ebede98bb11e9320f9
dnsmasq-debuginfo-2.48-13.el6.x86_64.rpm     MD5: 8f516ca900e8abfdef241dbab2c93a8f
SHA-256: 41bc5cbe1a9183df5a46c18b246f91a58b0d485207286647d1896de80e5c9eae
dnsmasq-utils-2.48-13.el6.x86_64.rpm     MD5: 590d6070f7f7ca6417bc1c947d67db87
SHA-256: 8e7e75cc678c254efac960a3cdc7f44204298c1f24e059fcafb2183ebcee8752
 
Red Hat Enterprise Linux HPC Node (v. 6)

SRPMS:
dnsmasq-2.48-13.el6.src.rpm     MD5: a5231f28d49afb08825e1f90ac6b84de
SHA-256: 76d7f65e8ec14e1fea6a0d0b69cb4dcb13ce1e28ac312a62850360e34a187d0d
 
x86_64:
dnsmasq-2.48-13.el6.x86_64.rpm     MD5: 593c4c51e3ac44528853afe36d8fd879
SHA-256: 31e8dd6523f064fe394b2a47a39525276275c22d7978d2ebede98bb11e9320f9
dnsmasq-debuginfo-2.48-13.el6.x86_64.rpm     MD5: 8f516ca900e8abfdef241dbab2c93a8f
SHA-256: 41bc5cbe1a9183df5a46c18b246f91a58b0d485207286647d1896de80e5c9eae
dnsmasq-utils-2.48-13.el6.x86_64.rpm     MD5: 590d6070f7f7ca6417bc1c947d67db87
SHA-256: 8e7e75cc678c254efac960a3cdc7f44204298c1f24e059fcafb2183ebcee8752
 
Red Hat Enterprise Linux Server (v. 6)

SRPMS:
dnsmasq-2.48-13.el6.src.rpm     MD5: a5231f28d49afb08825e1f90ac6b84de
SHA-256: 76d7f65e8ec14e1fea6a0d0b69cb4dcb13ce1e28ac312a62850360e34a187d0d
 
IA-32:
dnsmasq-2.48-13.el6.i686.rpm     MD5: ea20d0d6731b747d1cddb801df7c53db
SHA-256: bb285fe2631f788cb972a375fc6bd6bad55a865511b674a09611519e548a1f04
dnsmasq-debuginfo-2.48-13.el6.i686.rpm     MD5: d68b02afce84559c9b48dbfecf954d7b
SHA-256: 090a9e0e0fb03e96335a227839c16cebf875c809204986d07883994c029a85b6
dnsmasq-utils-2.48-13.el6.i686.rpm     MD5: 52d796d3d8bc39852e1d11667240e4c2
SHA-256: f14838f3a69a9797859e2f9698681c92e6811ef3e6bcc5b46aa83359857c02b5
 
PPC:
dnsmasq-2.48-13.el6.ppc64.rpm     MD5: 6bb11d72c75e6359f4383ec970d304c3
SHA-256: c8968b224f1fba1391a007d9bb4b2460a1c372f1042710db05bf73df0ea5e884
dnsmasq-debuginfo-2.48-13.el6.ppc64.rpm     MD5: fcf4fb31a71f0de603c1bd3ac76ae38f
SHA-256: 5a7106744b7ecd5429db1b9d8c428ccbf4f71ce4b365d4b24e378102d60d3498
dnsmasq-utils-2.48-13.el6.ppc64.rpm     MD5: 6c73ea6876ebcc97e1826a2c82c57a43
SHA-256: 45c98adbc9e9960bbcf9cd4b8baac4d3021dded7a02886e18c54b557be8fb843
 
s390x:
dnsmasq-2.48-13.el6.s390x.rpm     MD5: f3209ab0d4f11a0eaf065f9a76a42ec1
SHA-256: 1f357125baedb325ac284b9a8f4b863475ad60b596abf632f72445ed378d86af
dnsmasq-debuginfo-2.48-13.el6.s390x.rpm     MD5: 4d5f62ec02879189708ec74f01f9560c
SHA-256: e57d06fa36082978e7c83aa4c94be0332d6413cd2cf432b34c62409c49f39fc8
dnsmasq-utils-2.48-13.el6.s390x.rpm     MD5: 754e4b21fc7398789add077f74581c8b
SHA-256: 75fbd19d897c771eb419376915875cb358df9d605c5fc78b7eb6280908f48ed6
 
x86_64:
dnsmasq-2.48-13.el6.x86_64.rpm     MD5: 593c4c51e3ac44528853afe36d8fd879
SHA-256: 31e8dd6523f064fe394b2a47a39525276275c22d7978d2ebede98bb11e9320f9
dnsmasq-debuginfo-2.48-13.el6.x86_64.rpm     MD5: 8f516ca900e8abfdef241dbab2c93a8f
SHA-256: 41bc5cbe1a9183df5a46c18b246f91a58b0d485207286647d1896de80e5c9eae
dnsmasq-utils-2.48-13.el6.x86_64.rpm     MD5: 590d6070f7f7ca6417bc1c947d67db87
SHA-256: 8e7e75cc678c254efac960a3cdc7f44204298c1f24e059fcafb2183ebcee8752
 
Red Hat Enterprise Linux Workstation (v. 6)

SRPMS:
dnsmasq-2.48-13.el6.src.rpm     MD5: a5231f28d49afb08825e1f90ac6b84de
SHA-256: 76d7f65e8ec14e1fea6a0d0b69cb4dcb13ce1e28ac312a62850360e34a187d0d
 
IA-32:
dnsmasq-2.48-13.el6.i686.rpm     MD5: ea20d0d6731b747d1cddb801df7c53db
SHA-256: bb285fe2631f788cb972a375fc6bd6bad55a865511b674a09611519e548a1f04
dnsmasq-debuginfo-2.48-13.el6.i686.rpm     MD5: d68b02afce84559c9b48dbfecf954d7b
SHA-256: 090a9e0e0fb03e96335a227839c16cebf875c809204986d07883994c029a85b6
dnsmasq-utils-2.48-13.el6.i686.rpm     MD5: 52d796d3d8bc39852e1d11667240e4c2
SHA-256: f14838f3a69a9797859e2f9698681c92e6811ef3e6bcc5b46aa83359857c02b5
 
x86_64:
dnsmasq-2.48-13.el6.x86_64.rpm     MD5: 593c4c51e3ac44528853afe36d8fd879
SHA-256: 31e8dd6523f064fe394b2a47a39525276275c22d7978d2ebede98bb11e9320f9
dnsmasq-debuginfo-2.48-13.el6.x86_64.rpm     MD5: 8f516ca900e8abfdef241dbab2c93a8f
SHA-256: 41bc5cbe1a9183df5a46c18b246f91a58b0d485207286647d1896de80e5c9eae
dnsmasq-utils-2.48-13.el6.x86_64.rpm     MD5: 590d6070f7f7ca6417bc1c947d67db87
SHA-256: 8e7e75cc678c254efac960a3cdc7f44204298c1f24e059fcafb2183ebcee8752
 
(The unlinked packages above are only available from the Red Hat Network)

Bugs fixed (see bugzilla for more information)

833033 - CVE-2012-3411 libvirt+dnsmasq: DNS configured to answer DNS queries from non-virtual networks
850944 - "service dnsmasq restart (or dnsmasq package update) kills all instances of dnsmasq on system, including those started by libvirtd
884957 - guest can not get NAT IP from dnsmasq-2.48-10


References



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

The Red Hat security contact is secalert@redhat.com. More contact details at http://www.redhat.com/security/team/contact/