CVE 2006-1173
Sendmail before 8.13.7 allows remote attackers to cause a denial of service via deeply nested, malformed multipart MIME messages that exhaust the stack during the recursive mime8to7 function for performing 8-bit to 7-bit conversion, which prevents Sendmail from delivering queued messages and might lead to disk consumption by core dump files.
See the 
CVE page on Mitre.org
for more details.
