diff --git a/mozilla/webtools/bugzilla/buglist.cgi b/mozilla/webtools/bugzilla/buglist.cgi
index fa664c251c7..1c5161481cb 100755
--- a/mozilla/webtools/bugzilla/buglist.cgi
+++ b/mozilla/webtools/bugzilla/buglist.cgi
@@ -88,6 +88,16 @@ if ($::FORM{'format'} && $::FORM{'format'} eq "rdf" && !$::FORM{'ctype'}) {
     delete($::FORM{'format'});
 }
 
+# The js ctype presents a security risk; a malicious site could use it  
+# to gather information about secure bugs. So, we only allow public bugs to be
+# retrieved with this format.
+#
+# Note that if and when this call clears cookies or has other persistent 
+# effects, we'll need to do this another way instead.
+if ($::FORM{'ctype'} eq "js") {
+    Bugzilla->logout();
+}
+
 # Determine the format in which the user would like to receive the output.
 # Uses the default format if the user did not specify an output format;
 # otherwise validates the user's choice against the list of available formats.
diff --git a/mozilla/webtools/bugzilla/template/en/default/list/list.js.tmpl b/mozilla/webtools/bugzilla/template/en/default/list/list.js.tmpl
index 8dde0c5b7a1..e6bc794c2bc 100644
--- a/mozilla/webtools/bugzilla/template/en/default/list/list.js.tmpl
+++ b/mozilla/webtools/bugzilla/template/en/default/list/list.js.tmpl
@@ -18,6 +18,11 @@
   #
   # Contributor(s): Gervase Markham <gerv@gerv.net>
   #%]
+
+// Note: only publicly-accessible bugs (those not in any group) will be
+// listed when using this JavaScript format. This is to prevent malicious
+// sites stealing information about secure bugs.
+  
 bugs = new Array; 
 
 [% FOREACH bug = bugs %]