Blue Coat ProxySG before 6.2.14.1, 6.3.x, 6.4.x, and 6.5 before 6.5.2 allows remote attackers to cause a denial of service (memory consumption and dropped connections) via a recursive href in an HTML page, which triggers a large number of HTTP RW pipeline pre-fetch requests.
https://kb.bluecoat.com/index?page=content&id=SA75
http://www.securitytracker.com/id/1029088