RHSA-2015:2455 - Security Advisory

Topic

Updated unbound packages that fix one security issue and several bugs are
now available for Red Hat Enterprise Linux 7.

Red Hat Product Security has rated this update as having Low 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.

Description

The unbound packages provide a validating, recursive, and caching DNS or
DNSSEC resolver.

A denial of service flaw was found in unbound that an attacker could use to
trick the unbound resolver into following an endless loop of delegations,
consuming an excessive amount of resources. (CVE-2014-8602)

This update also fixes the following bugs:

• Prior to this update, there was a mistake in the time configuration in

the cron job invoking unbound-anchor to update the root zone key.
Consequently, unbound-anchor was invoked once a month instead of every day,
thus not complying with RFC 5011. The cron job has been replaced with a
systemd timer unit that is invoked on a daily basis. Now, the root zone key
validity is checked daily at a random time within a 24-hour window, and
compliance with RFC 5011 is ensured. (BZ#1180267)

• Previously, the unbound packages were installing their configuration file

for the systemd-tmpfiles utility into the /etc/tmpfiles.d/ directory. As a
consequence, changes to unbound made by the administrator in
/etc/tmpfiles.d/ could be overwritten on package reinstallation or update.
To fix this bug, unbound has been amended to install the configuration file
into the /usr/lib/tmpfiles.d/ directory. As a result, the system
administrator's configuration in /etc/tmpfiles.d/ is preserved, including
any changes, on package reinstallation or update. (BZ#1180995)

• The unbound server default configuration included validation of DNS

records using the DNSSEC Look-aside Validation (DLV) registry. The Internet
Systems Consortium (ISC) plans to deprecate the DLV registry service as no
longer needed, and unbound could execute unnecessary steps. Therefore, the
use of the DLV registry has been removed from the unbound server default
configuration. Now, unbound does not try to perform DNS records validation
using the DLV registry. (BZ#1223339)

All unbound users are advised to upgrade to these updated packages, which
contain backported patches to correct these issues.

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 Server 7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.5 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Extended Update Support 7.3 x86_64
• Red Hat Enterprise Linux Server - AUS 7.7 x86_64
• Red Hat Enterprise Linux Server - AUS 7.6 x86_64
• Red Hat Enterprise Linux Server - AUS 7.4 x86_64
• Red Hat Enterprise Linux Server - AUS 7.3 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support 7 x86_64
• Red Hat Enterprise Linux Workstation 7 x86_64
• Red Hat Enterprise Linux Desktop 7 x86_64
• Red Hat Enterprise Linux for IBM z Systems 7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.7 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.6 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.5 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.4 s390x
• Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 7.3 s390x
• Red Hat Enterprise Linux for Power, big endian 7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.7 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.6 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.5 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.4 ppc64
• Red Hat Enterprise Linux for Power, big endian - Extended Update Support 7.3 ppc64
• Red Hat Enterprise Linux for Scientific Computing 7 x86_64
• Red Hat Enterprise Linux Server from RHUI 7 x86_64
• Red Hat Enterprise Linux for Power, little endian 7 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.7 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.6 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.5 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.4 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.3 ppc64le
• Red Hat Enterprise Linux for Power, little endian - Extended Update Support 7.2 ppc64le
• Red Hat Enterprise Linux Server - TUS 7.7 x86_64
• Red Hat Enterprise Linux Server - TUS 7.6 x86_64
• Red Hat Enterprise Linux Server - TUS 7.3 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support (for IBM z Systems) 7 s390x
• Red Hat Enterprise Linux EUS Compute Node 7.7 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.6 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.5 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.4 x86_64
• Red Hat Enterprise Linux EUS Compute Node 7.3 x86_64
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 7.7 ppc64le
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 7.6 ppc64le
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 7.4 ppc64le
• Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 7.3 ppc64le
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.7 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.6 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.4 x86_64
• Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 7.3 x86_64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, big endian 7 ppc64
• Red Hat Enterprise Linux Server - Extended Life Cycle Support for IBM Power, little endian 7 ppc64le

Fixes

• BZ - 1172065 - CVE-2014-8602 unbound: specially crafted request can lead to denial of service
• BZ - 1180267 - root key management does not comply with RFC5011
• BZ - 1180995 - unbound is installing files under /etc/tmpfiles.d/

CVEs

• CVE-2014-8602

References

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