PGP SIGNED MESSAGE-----
CA-2003-01 Buffer Overflows in ISC DHCPD Minires Library
release date: January 15, 2003
Last revised: --
revision history can be found at the end of this file.
running ISC DHCPD versions 3.0 through 3.0.1RC10,
* For detailed vendor status information, see
Software Consortium (ISC) has discovered several buffer
overflow vulnerabilities in their implementation of DHCP (ISC DHCPD).
These vulnerabilities may allow remote attackers to execute arbitrary
code on affected systems. At this time, we are not aware of any
are multiple remote buffer overflow vulnerabilities in the ISC
implementation of DHCP. As described in RFC 2131, "the Dynamic
Configuration Protocol (DHCP) provides a framework for passing
configuration information to hosts on a TCP/IP network." In addition
supplying hosts with network configuration data, ISC DHCPD allows the
DHCP server to dynamically update a DNS server, eliminating the need
for manual updates to the name server configuration. Support for
dynamic DNS updates is provided by the NSUPDATE feature.
an internal source code audit, developers from the ISC
discovered several vulnerabilities in the error handling routines of
the minires library, which is used by NSUPDATE to resolve hostnames.
These vulnerabilities are stack-based buffer overflows that may be
exploitable by sending a DHCP message containing a large hostname
value. Note: Although the minires library is derived from the BIND 8
resolver library, these vulnerabilities do not affect any current
versions of BIND.
is tracking this issue as VU#284857. This reference number
corresponds to CVE candidate CAN-2003-0026.
attackers may be able to execute arbitrary code with the
privileges of the user running ISC DHCPD.
or apply a patch
has addressed these vulnerabilities in versions 3.0pl2 and
3.0.1RC11 of ISC DHCPD. If your software vendor supplies ISC DHCPD as
part of an operating system distribution, please see Appendix A for
vendor-specific patch information.
detailed list of vendors that have been notified of this issue by
the CERT/CC, please see
dynamic DNS updates (NSUPDATE)
interim measure, the ISC recommends disabling the NSUPDATE
feature on affected DHCP servers.
external access to DHCP server ports
interim measure, it is possible to limit exposure to these
vulnerabilities by restricting external access to affected DHCP servers
on the following ports:
67/tcp # Bootstrap Protocol Server
bootps 67/udp # Bootstrap Protocol Server
bootpc 68/tcp # Bootstrap Protocol Client
bootpc 68/udp # Bootstrap Protocol Client
the DHCP service
As a general
rule, the CERT/CC recommends disabling any service or
capability that is not explicitly required. Depending on your network
configuration, you may not need to use DHCP.
A. - Vendor Information
contains information provided by vendors for this
advisory. As vendors report new information to the CERT/CC, we will
update this section and note the changes in our revision history. If
particular vendor is not listed below, we have not received their
X and Mac OS X Server do not contain the vulnerability described
in this notice.
Software Design, Inc. (BSDI)
is addressed by the M431-001 and M500-004 patches
for the 4.3.1 and 5.0 versions of BSD/OS.
products have been found to be affected by this vulnerability.
Cisco products do utilize the ISC DHCPD, however, no Cisco
products implement the ISC DHCPD NSUPDATE feature, nor do they include
the minires library.
is not vulnerable as dhcpd is not supported on any of its
UXP/V OS is not vulnerable because it does not support the
Software Security Response Team
cross reference id: SSRT2423
HP-UX - not vulnerable
HP-MPE/ix - not vulnerable
HP Tru64 UNIX - not vulnerable
HP OpenVMS - not vulnerable
HP NonStop Servers - not vulnerable
To report potential security vulnerabilities in HP software,
send an E-mail message to: mailto:email@example.com
checked up on our router (Hitachi,Ltd. GR2000 series) about
[VU#284857]. Our DHCP implementation is NOT vulnerable.
AIX does not ship with the ISC DHCP daemon. The issues discussed
in VU#284857 or any following advisories based on this vulnerability
note do not pertain to AIX.
a patched version of 3.0 available (3.0pl2) and a new release
candidate for the next bug-fix release (3.0.1RC11). Both of these new
releases are available from http://www.isc.org/products/DHCP/.
MontaVista Software's Linux products are vulnerable to this
* EWS/UP 48 Series operating system
- is NOT vulnerable.
supported versions of NetBSD do not contain the error
handling routine vulnerabilities. Such vulnerabilities were fixed
prior to the release of NetBSD 1.5.
to the patch to ns_name.c, we believe that this is good
defensive programming and have applied the patch to NetBSD-current.
However, all calls to ns_name_ntol in the NetBSD source base pass a
correct, constant, non-zero value as the datsiz parameter.
NetBSD is not vulnerable.
is not vulnerable to this issue.
dhcp support is much modified, does not have that feature,
and therefore does not have that bug.
GNU/*/Linux is not vulnerable. We don't yet provide a DHCP
distributes a vulnerable version of ISC DHCP in Red Hat Linux
8.0. Other distributions of Red Hat Linux are not vulnerable to these
issues. New DHCP packages are available along with our advisory at the
URL below. Users of the Red Hat Network can update their systems using
the 'up2date' tool.
Networks is not vulnerable to VU#284857.
that we are not vulnerable to the issues described in
VU#284857. Solaris does not ship the ISC DHCPD and does not use any
the ISC DHCPD source in its version of DHCPD.
preparing updates, that will be released soon.
is aware of this vulnerability and is currently assessing all
products. This statement will be updated as new information becomes
Coordination Center thanks David Hankins of the Internet
Software Consortium for notifying us about this problem and for helping
us to construct this document. We also thank Jacques A. Vidrine for
drawing attention to this issue.
This document was written by Jeffrey P. Lanza.
is available from:
Phone: +1 412-268-7090 (24-hour hotline)
Fax: +1 412-268-6989
CERT Coordination Center
Software Engineering Institute
Carnegie Mellon University
Pittsburgh PA 15213-3890
personnel answer the hotline 08:00-17:00 EST(GMT-5) /
EDT(GMT-4) Monday through Friday; they are on call for emergencies
during other hours, on U.S. holidays, and on weekends.
urge you to encrypt sensitive information sent by email.
Our public PGP key is available from
prefer to use DES, please call the CERT hotline for more
and other security information are available from
our web site
to the CERT mailing list for advisories and bulletins,
send email to firstname.lastname@example.org. Please include in the body of your
and "CERT Coordination Center" are registered in the U.S.
Patent and Trademark Office.
Any material furnished by Carnegie Mellon University and the Software
Engineering Institute is furnished on an "as is" basis. Carnegie
Mellon University makes no warranties of any kind, either expressed
implied as to any matter including, but not limited to, warranty of
fitness for a particular purpose or merchantability, exclusivity or
results obtained from use of the material. Carnegie Mellon University
does not make any warranty of any kind with respect to freedom from
patent, trademark, or copyright infringement.
for use, disclaimers, and sponsorship information
2003 Carnegie Mellon University.
January 15, 2003: Initial release
Version: PGP 6.5.8
-----END PGP SIGNATURE-----