[krbdev.mit.edu #5853] apparent uninit length in ftpd.c:reply() [CVE-2007-5894]

[Tom Yu via RT]

This is one of the Venustech AD-LAB alleged vulnerabilities.

CVE-2007-5894
http://bugs.gentoo.org/show_bug.cgi?id=199205

This is not a vulnerability, and only a stylistic bug.  The alleged
vulnerability consists of reading an uninitialized variable, "length",
in the reply() function in src/appl/gssftp/ftpd/ftpd.c.

  1878                  /* Other auth types go here ... */
  1879                  if (length >= sizeof(in) / 4 * 3) {
  1880                          syslog(LOG_ERR, "input to radix_encode too long");
  1881                          fputs(in, stdout);
  1882                  } else if ((kerror = radix_encode(out, in, &length, 0))) {
  1883                          syslog(LOG_ERR, "Couldn't encode reply (%s)",
  1884                                          radix_error(kerror));
  1885                          fputs(in,stdout);

The "length" variable is only uninitialized if "auth_type" is neither
the "KERBEROS_V4" nor "GSSAPI"; this condition cannot occur in the
unmodified source code.  While the remote user can set the string in
"auth_type", this may only occur by way of the auth_data() function,
which will only set "auth_type" if it exactly matches one of the
aforementioned two strings.