BIND: Denial of service

Background

ISC BIND is the Internet Systems Consortium implementation of the Domain Name System (DNS) protocol.

Description

An unspecified improper usage of an already freed context has been reported. Additionally, an assertion error could be triggered in the DNSSEC validation of some responses to type ANY queries with multiple RRsets.

Impact

A remote attacker could crash the server through unspecified vectors or, if DNSSEC validation is enabled, by sending certain crafted ANY queries.

Workaround

There is no known workaround at this time for the first issue. The DNSSEC validation Denial of Service can be prevented by disabling DNSSEC validation until the upgrade to a fixed version. Note that DNSSEC validation is disabled on a default configuration.

Resolution

All ISC BIND 9.3 users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=net-dns/bind-9.3.4"

All ISC BIND 9.2 users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=net-dns/bind-9.2.8"