The garbage-collection implementation in Mozilla Firefox before 3.0.11, Thunderbird before 2.0.0.22, and SeaMonkey before 1.1.17 sets an element's owner document to null in unspecified circumstances, which allows remote attackers to execute arbitrary JavaScript with chrome privileges via a crafted event handler, related to an incorrect context for this event handler.

The JavaScript engine in Mozilla Firefox before 3.0.11, Thunderbird before 2.0.0.22, and SeaMonkey before 1.1.17 allows remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via vectors related to (1) js_LeaveSharpObject, (2) ParseXMLSource, and (3) a certain assertion in jsinterp.c; and other vectors.

Mozilla Firefox before 3.0.11 and SeaMonkey before 1.1.17 associate local documents with external domain names located after the file:// substring in a URL, which allows user-assisted remote attackers to read arbitrary cookies via a crafted HTML document, as demonstrated by a URL with file://example.com/C:/ at the beginning.

Mozilla Firefox before 3.0.11, Thunderbird before 2.0.0.22, and SeaMonkey before 1.1.17 allow remote attackers to cause a denial of service (memory corruption and application crash) or possibly execute arbitrary code via vectors involving "double frame construction."

js/src/xpconnect/src/xpcwrappedjsclass.cpp in Mozilla Firefox before 3.0.11, Thunderbird before 2.0.0.22, and SeaMonkey before 1.1.17 allows remote attackers to execute arbitrary web script with the privileges of a chrome object, as demonstrated by the browser sidebar and the FeedWriter.

Visual truncation vulnerability in netwerk/dns/src/nsIDNService.cpp in Mozilla Firefox before 3.0.11 and SeaMonkey before 1.1.17 allows remote attackers to spoof the location bar via an IDN with invalid Unicode characters that are displayed as whitespace, as demonstrated by the \u115A through \u115E characters.

Mozilla Firefox before 3.0.11, Thunderbird before 2.0.0.22, and SeaMonkey before 1.1.17 use the HTTP Host header to determine the context of a document provided in a non-200 CONNECT response from a proxy server, which allows man-in-the-middle attackers to execute arbitrary web script by modifying this CONNECT response, aka an "SSL tampering" attack.

The jar: URI implementation in Mozilla Firefox before 3.0.9, Thunderbird, and SeaMonkey does not follow the Content-Disposition header of the inner URI, which allows remote attackers to conduct cross-site scripting (XSS) attacks and possibly other attacks via an uploaded .jar file with a "Content-Disposition: attachment" designation.

Cross-site scripting (XSS) vulnerability in Mozilla Firefox before 3.0.9, Thunderbird, and SeaMonkey allows remote attackers to inject arbitrary web script or HTML via vectors involving XBL JavaScript bindings and remote stylesheets, as exploited in the wild by a March 2009 eBay listing.

Mozilla Firefox before 3.0.9 and SeaMonkey before 1.1.17 allow user-assisted remote attackers to obtain sensitive information via a web page with an embedded frame, which causes POST data from an outer page to be sent to the inner frame's URL during a SAVEMODE_FILEONLY save of the inner frame.