Launchpad.net

CVE 2009-0776

nsIRDFService in Mozilla Firefox before 3.0.7, Thunderbird before 2.0.0.21, and SeaMonkey before 1.1.15 allows remote attackers to bypass the same-origin policy and read XML data from another domain via a cross-domain redirect.

See the CVE page on Mitre.org for more details.