Directory Proxy Server (DPS) in Sun Java System Directory Server Enterprise Edition 6.0 through 6.3.1 does not enable the SO_KEEPALIVE socket option, which makes it easier for remote attackers to cause a denial of service (connection slot exhaustion) via multiple connections, aka Bug Id 6782659.
http://www.vupen.com/english/advisories/2009/3647
http://www.securitytracker.com/id?1023389
http://www.securityfocus.com/bid/37481
http://sunsolve.sun.com/search/document.do?assetkey=1-66-270789-1
http://sunsolve.sun.com/search/document.do?assetkey=1-21-141958-01-1