The Cisco Content Services Switch (CSS) 11500 with software 8.20.4.02 and the Application Control Engine (ACE) 4710 with software A2(3.0) do not properly handle LF header terminators in situations where the GET line is terminated by CRLF, which allows remote attackers to conduct HTTP request smuggling attacks and possibly bypass intended header insertions via crafted header data, as demonstrated by an LF character between the ClientCert-Subject and ClientCert-Subject-CN headers. NOTE: this vulnerability exists because of an incomplete fix for CVE-2010-1576.