GLSA 200807-08: BIND: Cache poisoning

http://security.gentoo.org/

Severity:	high
Title:	BIND: Cache poisoning
Date:	07/11/2008
Bugs:	#231201
ID:	200807-08

Synopsis

A weakness in the DNS protocol has been reported, which could lead to cache poisoning on recursive resolvers.

Background

ISC BIND is the Internet Systems Consortium implementation of the Domain Name System (DNS) protocol.

Affected packages

Package	Vulnerable	Unaffected	Architecture(s)
net-dns/bind	< 9.4.2_p1	>= 9.4.2_p1	All supported architectures

Description

Dan Kaminsky of IOActive has reported a weakness in the DNS protocol related to insufficient randomness of DNS transaction IDs and query source ports.

Impact

An attacker could exploit this weakness to poison the cache of a recursive resolver and thus spoof DNS traffic, which could e.g. lead to the redirection of web or mail traffic to malicious sites.

Workaround

There is no known workaround at this time.

Resolution

All BIND users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=net-dns/bind-9.4.2_p1"

Note: In order to utilize the query port randomization to mitigate the weakness, you need to make sure that your network setup allows the DNS server to use random source ports for query and that you have not set a fixed query port via the "query-source port" directive in the BIND configuration.

References

CVE-2008-1447

Availability

This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-200807-08.xml

Concerns?

Security is a primary focus of Gentoo Linux and ensuring the confidentiality and security of our users machines is of utmost importance to us. Any security concerns should be addressed to security@gentoo.org or alternatively, you may file a bug at https://bugs.gentoo.org.