The gss_userok function in appl/ftp/ftpd/gss_userok.c in Heimdal 0.7.2 does not allocate memory for the ticketfile pointer before calling free, which allows remote attackers to have an unknown impact via an invalid username. NOTE: the vulnerability was originally reported for ftpd.c, but this is incorrect.
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.