Updated bind packages that fix two security issues are now available for Red Hat Enterprise Linux 6.
The Red Hat Security Response Team has rated this update as having important security impact. Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) associated with each description below.
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.
It was discovered that named did not invalidate previously cached RRSIG records when adding an NCACHE record for the same entry to the cache. A remote attacker allowed to send recursive DNS queries to named could use this flaw to crash named.
It was discovered that, in certain cases, named did not properly perform DNSSEC validation of an NS RRset for zones in the middle of a DNSKEY algorithm rollover. This flaw could cause the validator to incorrectly determine that the zone is insecure and not protected by DNSSEC.
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.