The compress_add_dlabel_points function in dns/Compress.c in MaraDNS 1.4.03, 1.4.05, and probably other versions allows remote attackers to cause a denial of service (segmentation fault) and possibly execute arbitrary code via a long DNS hostname with a large number of labels, which triggers a heap-based buffer overflow.
Improper Restriction of Operations within the Bounds of a Memory Buffer The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary.