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.

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.

The view-source: URI implementation in Mozilla Firefox before 3.0.9, Thunderbird, and SeaMonkey does not properly implement the Same Origin Policy, which allows remote attackers to (1) bypass crossdomain.xml restrictions and connect to arbitrary web sites via a Flash file; (2) read, create, or modify Local Shared Objects via a Flash file; or (3) bypass unspecified restrictions and render content via vectors involving a jar: URI.

The JavaScript engine in Mozilla Firefox 3.x before 3.0.9, Thunderbird before 2.0.0.22, and SeaMonkey before 1.1.16 allows remote attackers to cause a denial of service (application crash) and possibly trigger memory corruption via vectors involving (1) js_FindPropertyHelper, related to the definitions of Math and Date; and (2) js_CheckRedeclaration.

Mozilla Firefox before 3.0.9, Thunderbird, and SeaMonkey do not properly implement the Same Origin Policy for (1) XMLHttpRequest, involving a mismatch for a document's principal, and (2) XPCNativeWrapper.toString, involving an incorrect __proto__ scope, which allows remote attackers to conduct cross-site scripting (XSS) attacks and possibly other attacks via a crafted document.

The browser engine in Mozilla Firefox before 3.0.9, Thunderbird before 2.0.0.22, and SeaMonkey before 1.1.16 allows remote attackers to cause a denial of service (application crash) and possibly trigger memory corruption via vectors related to nsSVGElement::BindToTree.

The browser engine in Mozilla Firefox 3.x before 3.0.9, Thunderbird before 2.0.0.22, and SeaMonkey before 1.1.16 allows remote attackers to cause a denial of service (application crash) and possibly trigger memory corruption via vectors related to (1) nsAsyncInstantiateEvent::Run, (2) nsStyleContext::Destroy, (3) nsComputedDOMStyle::GetWidth, (4) the xslt_attributeset_ImportSameName.html test case for the XSLT stylesheet compiler, (5) nsXULDocument::SynchronizeBroadcastListener, (6) IsBindingAncestor, (7) PL_DHashTableOperate and nsEditor::EndUpdateViewBatch, and (8) gfxSkipCharsIterator::SetOffsets, and other vectors.

The JavaScript engine in Mozilla Firefox before 3.0.9, Thunderbird before 2.0.0.22, and SeaMonkey before 1.1.16 allows remote attackers to cause a denial of service (application crash) and possibly trigger memory corruption via vectors involving JSOP_DEFVAR and properties that lack the JSPROP_PERMANENT attribute.