INFORMATION BULLETIN

S-358: DNS Vulnerability

[Debian Security Advisory DSA-1623-1]

August 18, 2008 18:00 GMT


PROBLEM:	The properties inherent to the DNS protocol lead to pratical DNS cache poisoning attacks. This can lead to misdirected web traffic and email rerouting.
PLATFORM:	Debian GNU/Linux 4.0 (etch)
DAMAGE:	DNS cache poisoning
SOLUTION:	Upgrade to the appropriate version.

VULNERABILITY ASSESSMENT:	The risk is HIGH. Successful attacks can lead to misdirected web traffic and email rerouting.

CVSS 2 BASE SCORE: TEMPORAL SCORE: VECTOR:	10.0 8.3 (AV:N/AC:L/Au:N/C:C/I:C/A:C/E:F/RL:OF/RC:C)

LINKS:
CIAC BULLETIN:	http://www.ciac.org/ciac/bulletins/s-358.shtml
ORIGINAL BULLETIN:	http://www.debian.org/security/2008/dsa-1623
CVE:	CVE-2008-1447

[***** Start Debian Security Advisory DSA-1623-1 *****]

Debian Security Advisory

DSA-1623-1 dnsmasq -- DNS cache poisoning

Date Reported:

31 Jul 2008

Affected Packages:

dnsmasq

Vulnerable:

Yes

Security database references:

In Mitre's CVE dictionary: CVE-2008-1447.

More information:

Dan Kaminsky discovered that properties inherent to the DNS protocol lead to practical DNS cache poisoning attacks. Among other things, successful attacks can lead to misdirected web traffic and email rerouting.

This update changes Debian's dnsmasq packages to implement the recommended countermeasure: UDP query source port randomization. This change increases the size of the space from which an attacker has to guess values in a backwards-compatible fashion and makes successful attacks significantly more difficult.

This update also switches the random number generator to Dan Bernstein's SURF.

For the stable distribution (etch), this problem has been fixed in version 2.35-1+etch4. Packages for alpha will be provided later.

For the unstable distribution (sid), this problem has been fixed in version 2.43-1.

We recommend that you upgrade your dnsmasq package.

Fixed in:

Debian GNU/Linux 4.0 (etch)

Source:: http://security.debian.org/pool/updates/main/d/dnsmasq/dnsmasq_2.35-1+etch4.dsc; http://security.debian.org/pool/updates/main/d/dnsmasq/dnsmasq_2.35.orig.tar.gz; http://security.debian.org/pool/updates/main/d/dnsmasq/dnsmasq_2.35-1+etch4.diff.gz
AMD64:: http://security.debian.org/pool/updates/main/d/dnsmasq/dnsmasq_2.35-1+etch4_amd64.deb
ARM:: http://security.debian.org/pool/updates/main/d/dnsmasq/dnsmasq_2.35-1+etch4_arm.deb
HP Precision:: http://security.debian.org/pool/updates/main/d/dnsmasq/dnsmasq_2.35-1+etch4_hppa.deb
Intel IA-32:: http://security.debian.org/pool/updates/main/d/dnsmasq/dnsmasq_2.35-1+etch4_i386.deb
Intel IA-64:: http://security.debian.org/pool/updates/main/d/dnsmasq/dnsmasq_2.35-1+etch4_ia64.deb
Big-endian MIPS:: http://security.debian.org/pool/updates/main/d/dnsmasq/dnsmasq_2.35-1+etch4_mips.deb
Little-endian MIPS:: http://security.debian.org/pool/updates/main/d/dnsmasq/dnsmasq_2.35-1+etch4_mipsel.deb
PowerPC:: http://security.debian.org/pool/updates/main/d/dnsmasq/dnsmasq_2.35-1+etch4_powerpc.deb
IBM S/390:: http://security.debian.org/pool/updates/main/d/dnsmasq/dnsmasq_2.35-1+etch4_s390.deb
Sun Sparc:: http://security.debian.org/pool/updates/main/d/dnsmasq/dnsmasq_2.35-1+etch4_sparc.deb

MD5 checksums of the listed files are available in the original advisory.


[***** End Debian Security Advisory DSA-1623-1 *****]

CIAC wishes to acknowledge the contributions of Debian for the information contained in this bulletin.

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