CVE 2008-0061
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."
See the 
CVE page on Mitre.org
for more details.
