The Abstract Window Toolkit (AWT) implementation in Sun Java SE 6 before Update 15 on X11 does not impose the intended constraint on distance from the window border to the Security Warning Icon, which makes it easier for context-dependent attackers to trick a user into interacting unsafely with an untrusted applet.
http://www.vupen.com/english/advisories/2009/3316
http://www.vmware.com/security/advisories/VMSA-2009-0016.html
http://www.securityfocus.com/archive/1/507985/100/0/threaded
http://security.gentoo.org/glsa/glsa-200911-02.xml
http://secunia.com/advisories/37460