BIND: Denial of Service — GLSA 200609-11

ISC BIND contains two vulnerabilities allowing a Denial of Service under certain conditions.

Affected Packages

net-dns/bind on all architectures
Affected versions < 9.3.2-r4
Unaffected versions >= 9.3.2-r4, revision >= 9.2.6-r4

Background

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

Description

Queries for SIG records will cause an assertion error if more than one SIG RRset is returned. Additionally, an INSIST failure can be triggered by sending multiple recursive queries if the response to the query arrives after all the clients looking for the response have left the recursion queue.

Impact

An attacker having access to a recursive server can crash the server by querying the SIG records where there are multiple SIG RRsets, or by sending many recursive queries in a short time. The exposure can be lowered by restricting the clients that can ask for recursion. An attacker can also crash an authoritative server serving a DNSSEC zone in which there are multiple SIG RRsets.

Workaround

There are no known workarounds at this time.

Resolution

All BIND 9.3 users should update to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=net-dns/bind-9.3.2-r4"

All BIND 9.2 users should update to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=net-dns/bind-9.2.6-r4"

References

Release Date
September 15, 2006

Latest Revision
September 15, 2006: 01

Severity
normal

Exploitable
remote

Bugzilla entries