7.1 - RHSA-2013:0550

Problem Description:

Updated bind packages that fix one security issue and add one enhancement are now available for Red Hat Enterprise Linux 6.

The Red Hat Security Response Team has rated this update as having moderate security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Desktop (v. 6) - i386, x86_64 Red Hat Enterprise Linux Desktop Optional (v. 6) - i386, x86_64 Red Hat Enterprise Linux HPC Node (v. 6) - x86_64 Red Hat Enterprise Linux HPC Node Optional (v. 6) - x86_64 Red Hat Enterprise Linux Server (v. 6) - i386, ppc64, s390x, x86_64 Red Hat Enterprise Linux Server Optional (v. 6) - i386, ppc64, s390x, x86_64 Red Hat Enterprise Linux Workstation (v. 6) - i386, x86_64 Red Hat Enterprise Linux Workstation Optional (v. 6) - i386, x86_64

3. Description:

The Berkeley Internet Name Domain (BIND) is an implementation of the Domain Name System (DNS) protocols. BIND includes a DNS server (named); a resolver library (routines for applications to use when interfacing with DNS); and tools for verifying that the DNS server is operating correctly. DNS64 is used to automatically generate DNS records so IPv6 based clients can access IPv4 systems through a NAT64 server.

A flaw was found in the DNS64 implementation in BIND when using Response Policy Zones (RPZ). If a remote attacker sent a specially-crafted query to a named server that is using RPZ rewrite rules, named could exit unexpectedly with an assertion failure. Note that DNS64 support is not enabled by default. (CVE-2012-5689)

This update also adds the following enhancement:

* Previously, it was impossible to configure the the maximum number of responses sent per second to one client. This allowed remote attackers to conduct traffic amplification attacks using DNS queries with spoofed source IP addresses. With this update, it is possible to use the new "rate-limit" configuration option in named.conf and configure the maximum number of queries which the server responds to. Refer to the BIND documentation for more details about the "rate-limit" option. (BZ#906312)

All bind users are advised to upgrade to these updated packages, which contain patches to correct this issue and add this enhancement. After installing the update, the BIND daemon (named) will be restarted automatically.

4. Solution:

Before applying this update, make sure all previously-released errata relevant to your system have been applied.

This update is available via the Red Hat Network. Details on how to use the Red Hat Network to apply this update are available at https://access.redhat.com/knowledge/articles/11258

5. Bugs fixed (http://bugzilla.redhat.com/):

903417 - CVE-2012-5689 bind: denial of service when processing queries and with both DNS64 and RPZ enabled 906312 - bind: Backport Response Rate Limiting (DNS RRL) patch into Red Hat Enterprise Linux 6