Squid, when transparent interception mode is enabled, uses the HTTP Host
header to determine the remote endpoint, which allows remote attackers to
bypass access controls for Flash, Java, Silverlight, and probably other
technologies, and possibly communicate with restricted intranet sites, via
a crafted web page that causes a client to send HTTP requests with a
modified Host header.
sbeattie> according to squid bug report, fixed in squid 3.2, which
sbeattie> hasn't us yet; bug report notes to *not* backport fix
mdeslaur> upstream doesn't consider the issue important enough to create
mdeslaur> a fix for <3.2. We aren't going to fix either.