Mozilla parsing error in E4X default namespace

Mozilla Firefox 3.x before 3.0.4, Firefox 2.x before 2.0.0.18, Thunderbird 2.x before 2.0.0.18, and SeaMonkey 1.x before 1.1.13 do not properly escape quote characters used for XML processing, which allows remote attackers to conduct XML injection attacks via the default namespace in an E4X...

Localstore.rdf XML injection through XULDocument.persist() — Mozilla

XULDocument.persist did not validate the attribute name, allowing an attacker to inject XML into localstore.rdf that would be read and acted upon at startup. This could include JavaScript commands that would be run with the permissions of the browser...