add clipboard data as a RemoteFlowSource

Author: erik-krogh

javascript/ql/lib/javascript.qll

@@ -78,6 +78,7 @@ import semmle.javascript.frameworks.ComposedFunctions
 import semmle.javascript.frameworks.Classnames
 import semmle.javascript.frameworks.ClassValidator
 import semmle.javascript.frameworks.ClientRequests
+import semmle.javascript.frameworks.Clipboard
 import semmle.javascript.frameworks.ClosureLibrary
 import semmle.javascript.frameworks.CookieLibraries
 import semmle.javascript.frameworks.Credentials

javascript/ql/lib/semmle/javascript/frameworks/Clipboard.qll

@@ -0,0 +1,63 @@
+/**
+ * Provides predicates for reasoning about clipboard data.
+ */
+
+import javascript
+
+/**
+ * Gets a jQuery "paste" event.
+ * E.g. `e` in `$("#foo").on("paste", function(e) { ... })`.
+ */
+private DataFlow::SourceNode jQueryPasteEvent(DataFlow::TypeTracker t) {
+  t.start() and
+  exists(DataFlow::CallNode call |
+    call = JQuery::objectRef().getAMethodCall(["bind", "on", "live", "one", "delegate"]) and
+    call.getArgument(0).mayHaveStringValue("paste")
+  |
+    result = call.getCallback(call.getNumArgument() - 1).getParameter(0)
+  )
+  or
+  exists(DataFlow::TypeTracker t2 | result = jQueryPasteEvent(t2).track(t2, t))
+}
+
+/**
+ * Gets a DOM "paste" event.
+ * E.g. `e` in `document.addEventListener("paste", e => { ... })`.
+ */
+private DataFlow::SourceNode pasteEvent(DataFlow::TypeTracker t) {
+  t.start() and
+  exists(DataFlow::CallNode call | call = DOM::domValueRef().getAMemberCall("addEventListener") |
+    call.getArgument(0).mayHaveStringValue("paste") and
+    result = call.getCallback(1).getParameter(0)
+  )
+  or
+  t.start() and
+  result = jQueryPasteEvent(DataFlow::TypeTracker::end()).getAPropertyRead("originalEvent")
+  or
+  exists(DataFlow::TypeTracker t2 | result = pasteEvent(t2).track(t2, t))
+}
+
+/**
+ * Gets a reference to the clipboardData DataTransfer object.
+ * https://developer.mozilla.org/en-US/docs/Web/API/ClipboardEvent/clipboardData
+ */
+private DataFlow::SourceNode clipboardDataTransferSource(DataFlow::TypeTracker t) {
+  t.start() and
+  exists(DataFlow::PropRead read | read = result |
+    read.getPropertyName() = "clipboardData" and
+    read.getBase().getALocalSource() = pasteEvent(DataFlow::TypeTracker::end())
+  )
+  or
+  exists(DataFlow::TypeTracker t2 | result = clipboardDataTransferSource(t2).track(t2, t))
+}
+
+/**
+ * A reference to data from the clipboard. Seen as a source for DOM-based XSS.
+ */
+private class ClipboardSource extends RemoteFlowSource {
+  ClipboardSource() {
+    this = clipboardDataTransferSource(DataFlow::TypeTracker::end()).getAMethodCall("getData")
+  }
+
+  override string getSourceType() { result = "Clipboard data" }
+}