RHSA-2010:0062 - Security Advisory

Topic

Updated bind packages that fix two security issues are now available for
Red Hat Enterprise Linux 5.

This update has been rated as having moderate security impact by the Red
Hat Security Response Team.

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.

A flaw was found in the BIND DNSSEC NSEC/NSEC3 validation code. If BIND was
running as a DNSSEC-validating resolver, it could incorrectly cache
NXDOMAIN responses, as if they were valid, for records proven by NSEC or
NSEC3 to exist. A remote attacker could use this flaw to cause a BIND
server to return the bogus, cached NXDOMAIN responses for valid records and
prevent users from retrieving those records (denial of service).
(CVE-2010-0097)

The original fix for CVE-2009-4022 was found to be incomplete. BIND was
incorrectly caching certain responses without performing proper DNSSEC
validation. CNAME and DNAME records could be cached, without proper DNSSEC
validation, when received from processing recursive client queries that
requested DNSSEC records but indicated that checking should be disabled. A
remote attacker could use this flaw to bypass the DNSSEC validation check
and perform a cache poisoning attack if the target BIND server was
receiving such client queries. (CVE-2010-0290)

All BIND users are advised to upgrade to these updated packages, which
contain a backported patch to resolve these issues. After installing the
update, the BIND daemon (named) will be restarted automatically.

Solution

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

This update is available via Red Hat Network. Details on how to use
the Red Hat Network to apply this update are available at
http://kbase.redhat.com/faq/docs/DOC-11259

Affected Products

• Red Hat Enterprise Linux Server 5 x86_64
• Red Hat Enterprise Linux Server 5 ia64
• Red Hat Enterprise Linux Server 5 i386
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.4 ia64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 5.4 i386
• Red Hat Enterprise Linux Workstation 5 x86_64
• Red Hat Enterprise Linux Workstation 5 i386
• Red Hat Enterprise Linux Desktop 5 x86_64
• Red Hat Enterprise Linux Desktop 5 i386
• Red Hat Enterprise Linux for IBM z Systems 5 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 5.4 s390x
• Red Hat Enterprise Linux for Power, big endian 5 ppc
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 5.4 ppc
• Red Hat Enterprise Linux Server from RHUI 5 x86_64
• Red Hat Enterprise Linux Server from RHUI 5 i386

Fixes

• BZ - 554851 - CVE-2010-0097 BIND DNSSEC NSEC/NSEC3 validation code could cause bogus NXDOMAIN responses
• BZ - 557121 - CVE-2010-0290 BIND upstream fix for CVE-2009-4022 is incomplete

CVEs

• CVE-2010-0097
• CVE-2010-0290
• CVE-2010-0382

References

• http://www.redhat.com/security/updates/classification/#moderate