Home / mailings [RHSA-2009:1238-01] Important: dnsmasq security update
Posted on 31 August 2009
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Red Hat Security Advisory
Synopsis: Important: dnsmasq security update
Advisory ID: RHSA-2009:1238-01
Product: Red Hat Enterprise Linux
Advisory URL: https://rhn.redhat.com/errata/RHSA-2009-1238.html
Issue date: 2009-08-31
CVE Names: CVE-2009-2957 CVE-2009-2958
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1. Summary:
An updated dnsmasq package that fixes two security issues is now available
for Red Hat Enterprise Linux 5.
This update has been rated as having important security impact by the Red
Hat Security Response Team.
2. Relevant releases/architectures:
Red Hat Enterprise Linux Desktop (v. 5 client) - i386, x86_64
Red Hat Enterprise Linux (v. 5 server) - i386, ia64, ppc, s390x, x86_64
3. Description:
Dnsmasq is a lightweight and easy to configure DNS forwarder and DHCP
server.
Core Security Technologies discovered a heap overflow flaw in dnsmasq when
the TFTP service is enabled (the "--enable-tftp" command line option, or by
enabling "enable-tftp" in "/etc/dnsmasq.conf"). If the configured tftp-root
is sufficiently long, and a remote user sends a request that sends a long
file name, dnsmasq could crash or, possibly, execute arbitrary code with
the privileges of the dnsmasq service (usually the unprivileged "nobody"
user). (CVE-2009-2957)
A NULL pointer dereference flaw was discovered in dnsmasq when the TFTP
service is enabled. This flaw could allow a malicious TFTP client to crash
the dnsmasq service. (CVE-2009-2958)
Note: The default tftp-root is "/var/ftpd", which is short enough to make
it difficult to exploit the CVE-2009-2957 issue; if a longer directory name
is used, arbitrary code execution may be possible. As well, the dnsmasq
package distributed by Red Hat does not have TFTP support enabled by
default.
All users of dnsmasq should upgrade to this updated package, which contains
a backported patch to correct these issues. After installing the updated
package, the dnsmasq service must be restarted for the update to take
effect.
4. Solution:
Before applying this update, make sure that all previously-released
errata relevant to your system have been applied.
This update is available via Red Hat Network. Details on how to use
the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/docs/DOC-11259
5. Bugs fixed (http://bugzilla.redhat.com/):
519020 - CVE-2009-2957, CVE-2009-2958 dnsmasq: multiple vulnerabilities in TFTP server
6. Package List:
Red Hat Enterprise Linux Desktop (v. 5 client):
Source:
ftp://ftp.redhat.com/pub/redhat/linux/enterprise/5Client/en/os/SRPMS/dnsmasq-2.45-1.1.el5_3.src.rpm
i386:
dnsmasq-2.45-1.1.el5_3.i386.rpm
dnsmasq-debuginfo-2.45-1.1.el5_3.i386.rpm
x86_64:
dnsmasq-2.45-1.1.el5_3.x86_64.rpm
dnsmasq-debuginfo-2.45-1.1.el5_3.x86_64.rpm
Red Hat Enterprise Linux (v. 5 server):
Source:
ftp://ftp.redhat.com/pub/redhat/linux/enterprise/5Server/en/os/SRPMS/dnsmasq-2.45-1.1.el5_3.src.rpm
i386:
dnsmasq-2.45-1.1.el5_3.i386.rpm
dnsmasq-debuginfo-2.45-1.1.el5_3.i386.rpm
ia64:
dnsmasq-2.45-1.1.el5_3.ia64.rpm
dnsmasq-debuginfo-2.45-1.1.el5_3.ia64.rpm
ppc:
dnsmasq-2.45-1.1.el5_3.ppc.rpm
dnsmasq-debuginfo-2.45-1.1.el5_3.ppc.rpm
s390x:
dnsmasq-2.45-1.1.el5_3.s390x.rpm
dnsmasq-debuginfo-2.45-1.1.el5_3.s390x.rpm
x86_64:
dnsmasq-2.45-1.1.el5_3.x86_64.rpm
dnsmasq-debuginfo-2.45-1.1.el5_3.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://www.redhat.com/security/team/key/#package
7. References:
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-2957
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2009-2958
http://www.redhat.com/security/updates/classification/#important
8. Contact:
The Red Hat security contact is <secalert@redhat.com>. More contact
details at https://www.redhat.com/security/team/contact/
Copyright 2009 Red Hat, Inc.
