1 files changed, 4 insertions, 0 deletions
diff --git a/Bugzilla/CGI.pm b/Bugzilla/CGI.pm
index e0e1c40ba..9d8a1c48f 100644
--- a/Bugzilla/CGI.pm
+++ b/Bugzilla/CGI.pm
@@ -306,6 +306,10 @@ sub header {
         unshift(@_, '-x_frame_options' => 'SAMEORIGIN');
     }
 
+    # Add X-XSS-Protection header to prevent simple XSS attacks
+    # and enforce the blocking (rather than the rewriting) mode.
+    unshift(@_, '-x_xss_protection' => '1; mode=block');
+
     return $self->SUPER::header(@_) || "";
 }