The proxy-cache implementation in Cisco AsyncOS 8.0.x before 8.0.7-151, 8.1.x and 8.5.x before 8.5.2-004, 8.6.x and 8.7.x before 8.7.0-171-LD, and 8.8.x before 8.8.0-085 on Web Security Appliance (WSA) devices allows remote attackers to cause a denial of service (memory consumption) via multiple proxy connections, aka Bug ID CSCus10922.
http://www.securitytracker.com/id/1034062
http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20151104-wsa1