Buffer overflow in NetWin SurgeFTP before 23d2 allows remote attackers to cause a denial of service (crash) or possibly execute arbitrary code via a long string within the authentication request.
The administration web interface in NetWin SurgeFTP 2.3a2 and earlier allows remote attackers to cause a denial of service (daemon crash) via a large integer in the Content-Length HTTP header, which triggers a NULL pointer dereference when memory allocation fails.
cgi/surgeftpmgr.cgi (aka the Web Manager interface on TCP port 7021 or 9021) in NetWin SurgeFTP version 23f2 has XSS via the classid, domainid, or username parameter.