Security researcher Gregory Fleischer reported that when a Java LiveConnect script was loaded via a data: URL which redirects via a meta refresh, then the resulting plugin object was created with the wrong security principal and thus received elevated privileges such as the abilities to read local files, launch processes, and create network connections.
This is now public: http://www.mozilla.org/security/announce/2010/mfsa2010-79.html
This issue has been addressed in following products: Red Hat Enterprise Linux 4 Red Hat Enterprise Linux 5 Red Hat Enterprise Linux 6 Via RHSA-2010:0966 https://rhn.redhat.com/errata/RHSA-2010-0966.html
This issue has been addressed in following products: Red Hat Enterprise Linux 4 Via RHSA-2010:0967 https://rhn.redhat.com/errata/RHSA-2010-0967.html