7.8 - RHSA-2016:0078

Problem Description:

Updated bind packages that fix multiple security issues are now available for Red Hat Enterprise Linux 6.4 and 6.5 Advanced 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.

2. Relevant releases/architectures:

Red Hat Enterprise Linux Server AUS (v. 6.4) - i386, ppc64, s390x, x86_64 Red Hat Enterprise Linux Server AUS (v. 6.5) - i386, ppc64, s390x, x86_64 Red Hat Enterprise Linux Server Optional AUS (v. 6.4) - i386, ppc64, s390x, x86_64 Red Hat Enterprise Linux Server Optional AUS (v. 6.5) - i386, ppc64, s390x, 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.

A denial of service flaw was found in the way BIND followed DNS delegations. A remote attacker could use a specially crafted zone containing a large number of referrals which, when looked up and processed, would cause named to use excessive amounts of memory or crash. (CVE-2014-8500)

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.

4. 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

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

1171912 - CVE-2014-8500 bind: delegation handling denial of service 1247361 - CVE-2015-5477 bind: TKEY query handling flaw leading to denial of service 1259087 - CVE-2015-5722 bind: malformed DNSSEC key failed assertion denial of service 1291176 - CVE-2015-8000 bind: responses with a malformed class attribute can trigger an assertion failure in db.c