[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
[FreeBSD] Schwachstellen im ISC Bind Nameserver - FreeBSD-SA-07:02.bind
-----BEGIN PGP SIGNED MESSAGE-----
Hash: MD5
Liebe Kolleginnen und Kollegen,
soeben erreichte uns nachfolgende Warnung des FreeBSD Security Officers.
Wir geben diese Informationen unveraendert an Sie weiter.
CVE-2007-0493 - Schwachstelle im ISC BIND Nameserver
Im ISC BIND Nameserver wird unter Umstaenden auf eine Speicherstruktur
zugegriffen, die bereits freigegeben worden ist. Folge davon ist ein
Absturz des Nameservers. Ein entfernter Angreifer kann diese
Schwachstelle ausnutzen, um einen Denial of Service Angriff auf den
Nameserver durchzufuehren. Voraussetzung ist, dass rekursive Anfragen
unterstuetzt werden.
CVE-2007-0494 - Schwachstelle im ISC BIND Nameserver
Im ISC BIND Nameserver ist eine Schwachstelle bei der Bearbeitung von
Antworten auf DNS-Anfragen vorhanden. Ein entfernter Angreifer kann
diese Schwachstelle mittels einer speziell konstruierten DNS-Antwort
(Query Response vom Typ "any") ausnutzen, um den Server zum Absturz zu
bringen. Voraussetzung fuer das Ausnutzen der Schwachstelle ist, dass
die DNSSEC Erweiterungen verwendet werden.
Betroffen sind die folgenden Software Pakete und Plattformen:
Modul bind
FreeBSD 5.3, 5.5, 6.1 und 6.2 vor dem entsprechenden Korrekturdatum:
2007-02-07 00:42:09 UTC (RELENG_6, 6.2-STABLE)
2007-02-09 20:24:15 UTC (RELENG_6_2, 6.2-RELEASE-p1)
2007-02-09 20:23:29 UTC (RELENG_6_1, 6.1-RELEASE-p13)
2007-02-07 00:46:35 UTC (RELENG_5, 5.5-STABLE)
2007-02-09 20:22:44 UTC (RELENG_5_5, 5.5-RELEASE-p11)
Vom Hersteller werden ueberarbeitete Pakete zur Verfuegung gestellt.
Hersteller Advisory:
http://security.freebsd.org/advisories/FreeBSD-SA-07:02.bind.asc
(c) der deutschen Zusammenfassung bei DFN-CERT Services GmbH; die
Verbreitung, auch auszugsweise, ist nur unter Hinweis auf den Urheber,
DFN-CERT Services GmbH, und nur zu nicht kommerziellen Zwecken
gestattet.
Mit freundlichen Gruessen,
Klaus Moeller, DFN-CERT
- -----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
=============================================================================
FreeBSD-SA-07:02.bind Security Advisory
The FreeBSD Project
Topic: Multiple Denial of Service vulnerabilities in named(8)
Category: contrib
Module: bind
Announced: 2007-02-09
Affects: FreeBSD 5.3 and later.
Corrected: 2007-02-07 00:42:09 UTC (RELENG_6, 6.2-STABLE)
2007-02-09 20:24:15 UTC (RELENG_6_2, 6.2-RELEASE-p1)
2007-02-09 20:23:29 UTC (RELENG_6_1, 6.1-RELEASE-p13)
2007-02-07 00:46:35 UTC (RELENG_5, 5.5-STABLE)
2007-02-09 20:22:44 UTC (RELENG_5_5, 5.5-RELEASE-p11)
CVE Name: CVE-2007-0493, CVE-2007-0494
For general information regarding FreeBSD Security Advisories,
including descriptions of the fields above, security branches, and the
following sections, please visit <URL:http://security.FreeBSD.org/>.
I. Background
BIND 9 is an implementation of the Domain Name System (DNS) protocols.
The named(8) daemon is an Internet domain name server. DNS Security
Extensions (DNSSEC) are additional protocol options that add
authentication and integrity to the DNS protocols.
II. Problem Description
A type * (ANY) query response containing multiple RRsets can trigger an
assertion failure.
Certain recursive queries can cause the nameserver to crash by using memory
which has already been freed.
III. Impact
A remote attacker sending a type * (ANY) query to an authoritative DNS
server for a DNSSEC signed zone can cause the named(8) daemon to exit,
resulting in a Denial of Service.
A remote attacker sending recursive queries can cause the nameserver to
crash, resulting in a Denial of Service.
IV. Workaround
There is no workaround available, but systems which are not authoritative
servers for DNSSEC signed zones are not affected by the first issue; and
systems which do not permit untrusted users to perform recursive DNS
resolution are not affected by the second issue. Note that the default
configuration for named(8) in FreeBSD allows local access only (which on
many systems is equivalent to refusing access to untrusted users).
V. Solution
Perform one of the following:
1) Upgrade your vulnerable system to 5-STABLE, or 6-STABLE, or to the
RELENG_6_2, RELENG_6_1, or RELENG_5_5 security branch dated after the
correction date.
2) To patch your present system:
The following patches have been verified to apply to FreeBSD 5.5, 6.1,
and 6.2 systems.
a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.
[FreeBSD 5.5, FreeBSD 6.1]
# fetch http://security.FreeBSD.org/patches/SA-07:02/bind61.patch
# fetch http://security.FreeBSD.org/patches/SA-07:02/bind61.patch.asc
[FreeBSD 6.2]
# fetch http://security.FreeBSD.org/patches/SA-07:02/bind62.patch
# fetch http://security.FreeBSD.org/patches/SA-07:02/bind62.patch.asc
b) Execute the following commands as root:
# cd /usr/src
# patch < /path/to/patch
# cd /usr/src/lib/bind
# make obj && make depend && make && make install
# cd /usr/src/usr.sbin/named
# make obj && make depend && make && make install
c) Restart the named application:
# /etc/rc.d/named restart
VI. Correction details
The following list contains the revision numbers of each file that was
corrected in FreeBSD.
Branch Revision
Path
- - -------------------------------------------------------------------------
RELENG_5
src/contrib/bind9/lib/dns/resolver.c 1.1.1.1.2.8
src/contrib/bind9/lib/dns/validator.c 1.1.1.1.2.5
src/contrib/bind9/lib/dns/include/dns/validator.h 1.1.1.1.2.4
RELENG_5_5
src/UPDATING 1.342.2.35.2.11
src/sys/conf/newvers.sh 1.62.2.21.2.13
src/contrib/bind9/lib/dns/resolver.c 1.1.1.1.2.4.2.2
src/contrib/bind9/lib/dns/validator.c 1.1.1.1.2.3.2.1
src/contrib/bind9/lib/dns/include/dns/validator.h 1.1.1.1.2.2.2.1
RELENG_6
src/contrib/bind9/lib/dns/resolver.c 1.1.1.2.2.6
src/contrib/bind9/lib/dns/validator.c 1.1.1.2.2.3
src/contrib/bind9/lib/dns/include/dns/validator.h 1.1.1.1.4.3
RELENG_6_2
src/UPDATING 1.416.2.29.2.4
src/sys/conf/newvers.sh 1.69.2.13.2.4
src/contrib/bind9/lib/dns/resolver.c 1.1.1.2.2.4.2.2
src/contrib/bind9/lib/dns/validator.c 1.1.1.2.2.1.4.2
src/contrib/bind9/lib/dns/include/dns/validator.h 1.1.1.1.4.1.4.2
RELENG_6_1
src/UPDATING 1.416.2.22.2.15
src/sys/conf/newvers.sh 1.69.2.11.2.15
src/contrib/bind9/lib/dns/resolver.c 1.1.1.2.2.2.2.2
src/contrib/bind9/lib/dns/validator.c 1.1.1.2.2.1.2.1
src/contrib/bind9/lib/dns/include/dns/validator.h 1.1.1.1.4.1.2.1
- - -------------------------------------------------------------------------
VII. References
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-0493
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-0494
The latest revision of this advisory is available at
http://security.FreeBSD.org/advisories/FreeBSD-SA-07:02.bind.asc
- -----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.6 (FreeBSD)
iD8DBQFFzNnpFdaIBMps37IRAsCVAJ9qvyFe04YWnkvYkFQPsSTIP+SLYgCfUhO8
alXiQEsy1iSwSI66d/e7gSk=
=HmF6
- -----END PGP SIGNATURE-----
- --
Dipl. Inform. Klaus Moeller (CSIRT)
DFN-CERT Services GmbH, https://www.dfn-cert.de, Phone +49 40 808077-555
Sitz / Register: Hamburg, AG Hamburg, HRB 88805, Ust-IdNr.: DE 232129737
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.2 (GNU/Linux)
iQEVAwUBRdCH4hYd1iQZmhQQAQFLgAf/Vh6JQrTr6Vd1v8557uR7j09aAUP956Fr
dkxjrtva30+rySJVNoEYPCyyq6n8vyioHdqi3E/DkBsnPD0Cr/ZUq8QOLxB4PCfc
EkUJ+iCkBgSLRGpgK0Z1SeG4XAIV89sJ0vjpnq4GI9gImvuFzAub2QUHU4/FIVpt
m70iLIu0+0kWhk4ANR1jL0p/4LCbbwGxFO9q4tXdsB8u3evMIAk0C07yEt9qzzLY
BgAxjjBRKOVwfOWX626yUdsLc7BeLLz0tOwRLBNzj+QL0ilKGocjTTJ/1Md76ewt
BEaWfe16F+Rm6Cu+/p0/MldpBqaYhDa4jrGyMz6L3I5AF7IoWaM7bQ==
=1UZx
-----END PGP SIGNATURE-----