The bftpdutmp_log function in bftpdutmp.c in Bftpd before 2.4 does not place a '\0' character at the end of the string value of the ut.bu_host structure member, which might allow remote attackers to cause a denial of service (daemon crash) via unspecified vectors. NOTE: some of these details are obtained from third party information.
http://www.vupen.com/english/advisories/2009/3032
http://www.securityfocus.com/bid/36820
http://secunia.com/advisories/37185