MaraDNS: CNAME Denial of Service

1. Gentoo Linux Security Advisory

Advisory Reference	GLSA 200801-16 / maradns
Release Date	January 29, 2008
Latest Revision	January 29, 2008: 01
Impact	normal
Exploitable	remote

Package	Vulnerable versions	Unaffected versions	Architecture(s)
net-dns/maradns	< 1.2.12.08	>= 1.2.12.08	All supported architectures

Related bugreports: #204351

Synopsis

MaraDNS is prone to a Denial of Service vulnerability impacting CNAME resolution.

2. Impact Information

Background

MaraDNS is a package that implements the Domain Name Service (DNS) with resolver and caching ability.

Description

Michael Krieger reported that a specially crafted DNS could prevent an authoritative canonical name (CNAME) record from being resolved because of an "improper rotation of resource records".

Impact

A remote attacker could send specially crafted DNS packets to a vulnerable server, making it unable to resolve CNAME records.

3. Resolution Information

Workaround

Add "max_ar_chain = 2" to the "marac" configuration file.

Resolution

All MaraDNS users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge --sync
# emerge --ask --oneshot --verbose ">=net-dns/maradns-1.2.12.09"

4. References

CVE-2008-0061

Updated January 29, 2008

Summary: This is a Gentoo Linux Security Advisory

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