Describe CVE-2007-5939.
What is CVE-2007-5939?
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..