Off-by-one error in the do_login_loop function in libwzd-core/wzd_login.c in wzdftpd 0.8.0, 0.8.2, and possibly other versions allows remote attackers to cause a denial of service (daemon crash) via a long USER command that triggers a stack-based buffer overflow. NOTE: some of these details are obtained from third party information.
https://www.exploit-db.com/exploits/4498
https://exchange.xforce.ibmcloud.com/vulnerabilities/37010
https://exchange.xforce.ibmcloud.com/vulnerabilities/37008
http://www.vupen.com/english/advisories/2007/3389
http://www.securityfocus.com/bid/25967
http://www.debian.org/security/2008/dsa-1452