MaraDNS 1.0 before 1.0.41, 1.2 before 1.2.12.08, and 1.3 before 1.3.07.04 allows remote attackers to cause a denial of service via a crafted DNS packet that prevents an authoritative name (CNAME) record from resolving, aka "improper rotation of resource records."
http://www.vupen.com/english/advisories/2008/0026
http://www.securityfocus.com/bid/27124
http://www.maradns.org/changelog.html
http://www.debian.org/security/2008/dsa-1445
http://security.gentoo.org/glsa/glsa-200801-16.xml
http://secunia.com/advisories/28650
http://secunia.com/advisories/28334
http://secunia.com/advisories/28329
http://maradns.blogspot.com/2007/08/maradns-update-all-versions.html