Multiple buffer overflows in NEC SOCKS5 1.0 r11 and earlier allow remote attackers to cause a denial of service and possibly execute arbitrary code via a long username to (1) the GetString function in proxy.c for the SOCKS5 module or (2) the HandleS4Connection function in proxy.c for the SOCKS4 module.
http://www.securityfocus.com/bid/5147