RHSA-2016:0079 - Security Advisory

Topic

Updated bind packages that fix three security issues are now available for
Red Hat Enterprise Linux 6.6 Extended Update Support.

Red Hat Product Security has rated this update as having Important security
impact. Common Vulnerability Scoring System (CVSS) base scores, which give
detailed severity ratings, are available for each vulnerability from the
CVE links in the References section.

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 way BIND handled requests for TKEY DNS resource
records. A remote attacker could use this flaw to make named (functioning
as an authoritative DNS server or a DNS resolver) exit unexpectedly with an
assertion failure via a specially crafted DNS request packet.
(CVE-2015-5477)

A denial of service flaw was found in the way BIND parsed certain malformed
DNSSEC keys. A remote attacker could use this flaw to send a specially
crafted DNS query (for example, a query requiring a response from a zone
containing a deliberately malformed key) that would cause named functioning
as a validating resolver to crash. (CVE-2015-5722)

A denial of service flaw was found in the way BIND processed certain
records with malformed class attributes. A remote attacker could use this
flaw to send a query to request a cached record with a malformed class
attribute that would cause named functioning as an authoritative or
recursive server to crash. (CVE-2015-8000)

Note: This issue affects authoritative servers as well as recursive
servers, however authoritative servers are at limited risk if they perform
authentication when making recursive queries to resolve addresses for
servers listed in NS RRSETs.

Red Hat would like to thank ISC for reporting the CVE-2015-5477,
CVE-2015-5722, and CVE-2015-8000 issues. Upstream acknowledges Jonathan
Foote as the original reporter of CVE-2015-5477, and Hanno Böck as the
original reporter of CVE-2015-5722.

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

Solution

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

For details on how to apply this update, refer to:

https://access.redhat.com/articles/11258

Affected Products

• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 6.6 i386
• Red Hat Enterprise Linux Server - AUS 6.6 x86_64
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 6.6 s390x
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 6.6 ppc64
• Red Hat Enterprise Linux Server - TUS 6.6 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.6 x86_64
• Red Hat Enterprise Linux Server - Extended Update Support from RHUI 6.6 i386
• Red Hat Enterprise Linux EUS Compute Node 6.6 x86_64

Fixes

• BZ - 1247361 - CVE-2015-5477 bind: TKEY query handling flaw leading to denial of service
• BZ - 1259087 - CVE-2015-5722 bind: malformed DNSSEC key failed assertion denial of service
• BZ - 1291176 - CVE-2015-8000 bind: responses with a malformed class attribute can trigger an assertion failure in db.c

CVEs

• CVE-2015-5477
• CVE-2015-5722
• CVE-2015-8000

References

• https://access.redhat.com/security/updates/classification/#important
• https://kb.isc.org/article/AA-01272
• https://kb.isc.org/article/AA-01287
• https://kb.isc.org/article/AA-01317