Several vulnerabilities have been discovered in Icedove, a mail client based on Thunderbird. CVE-2011-3647 The JSSubScriptLoader does not properly handle XPCNativeWrappers during calls to the loadSubScript method in an add-on, which makes it easier for remote attackers to gain privileges via a crafted web site that leverages certain unwrapping behavior. CVE-2011-3648 A cross-site scripting vulnerability allows remote attackers to inject arbitrary web script or HTML via crafted text with Shift JIS encoding. CVE-2011-3650 Iceweasel does not properly handle JavaScript files that contain many functions, which allows user-assisted remote attackers to cause a denial of service or possibly have unspecified other impact via a crafted file that is accessed by debugging APIs, as demonstrated by Firebug.