GuildFTPd 0.999.14, and possibly other versions, allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via long arguments to the CWD and LIST commands, which triggers heap corruption related to an improper free call, and possibly triggering 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.