GLSA 200908-02: BIND: Denial of Service

http://security.gentoo.org/

Severity:	normal
Title:	BIND: Denial of Service
Date:	08/01/2009
Bugs:	#279508
ID:	200908-02

Synopsis

Dynamic Update packets can cause a Denial of Service in the BIND daemon.

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	< 9.4.3_p3	>= 9.4.3_p3	All supported architectures

Description

Matthias Urlichs reported that the dns_db_findrdataset() function fails when the prerequisite section of the dynamic update message contains a record of type "ANY" and where at least one RRset for this FQDN exists on the server.

Impact

A remote unauthenticated attacker could send a specially crafted dynamic update message to the BIND daemon (named), leading to a Denial of Service (daemon crash). This vulnerability affects all primary (master) servers -- it is not limited to those that are configured to allow dynamic updates.

Workaround

Configure a firewall that performs Deep Packet Inspection to prevent nsupdate messages from reaching named. Alternatively, expose only secondary (slave) servers to untrusted networks.

Resolution

All BIND users should upgrade to the latest version:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=net-dns/bind-9.4.3_p3"

References

Availability

This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-200908-02.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.