The Berkeley Internet Name Domain is an implementation of the Domain Name System protocols. BIND includes a DNS server ; a resolver library ; and tools for verifying that the DNS server is operating correctly. 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. 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 this issue. All bind users are advised to upgrade to these updated packages, which contain a backported patch to correct this issue. After installing the update, the BIND daemon will be restarted automatically.