BIND: Denial of Service

1. Gentoo Linux Security Advisory

Advisory Reference	GLSA 200609-11 / bind
Release Date	September 15, 2006
Latest Revision	September 15, 2006: 01
Impact	normal
Exploitable	remote

Package	Vulnerable versions	Unaffected versions	Architecture(s)
net-dns/bind	< 9.3.2-r4	>= 9.3.2-r4, revision >= 9.2.6-r4	All supported architectures

Related bugreports: #146486

Synopsis

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

2. Impact Information

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.

3. Resolution Information

Workaround

There are no known workarounds at this time.

Resolution

All BIND 9.3 users should update to the latest version:

Code Listing 3.1: Resolution

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

All BIND 9.2 users should update to the latest version:

Code Listing 3.2: Resolution

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

4. References

Page updated September 15, 2006

Summary: This is a Gentoo Linux Security Advisory

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