The Java Web Start implementation in Sun Java SE 6 before Update 17 does not properly handle the interaction between a signed JAR file and a JNLP (1) application or (2) applet, which has unspecified impact and attack vectors, related to a "regression," aka Bug Id 6870531.
https://oval.cisecurity.org/repository/search/definition/oval%3Aorg.mitre.oval%3Adef%3A6794
https://bugzilla.redhat.com/show_bug.cgi?id=532914
http://security.gentoo.org/glsa/glsa-200911-02.xml