Mozilla security researcher moz_bug_r_a4 reported a cross-site scripting (XSS) attack through the context menu using a data: URL. In this issue, context menu functionality ("View Image", "Show only this frame", and "View background image") are disallowed in a javascript: URL but allowed in a data: URL, allowing for XSS. This can lead to arbitrary code execution. Reference: http://www.mozilla.org/security/announce/2012/mfsa2012-46.html
Acknowledgements: Red Hat would like to thank the Mozilla project for reporting this issue. Upstream acknowledges moz_bug_r_a4 as the original reporter of this issue.
This issue has been addressed in following products: Red Hat Enterprise Linux 5 Red Hat Enterprise Linux 6 Via RHSA-2012:1088 https://rhn.redhat.com/errata/RHSA-2012-1088.html