Merge branch 'security-stable-1.651' into security-stable-2.7

core/src/main/java/hudson/PluginManager.java

@@ -1281,6 +1281,7 @@ public abstract class PluginManager extends AbstractModelObject implements OnMas
         return hudson.util.HttpResponses.okJSON(response);
     }
 
+    @RequirePOST
     public HttpResponse doUpdateSources(StaplerRequest req) throws IOException {
         Jenkins.getInstance().checkPermission(CONFIGURE_UPDATECENTER);
 
@@ -1315,6 +1316,7 @@ public abstract class PluginManager extends AbstractModelObject implements OnMas
     /**
      * Performs the installation of the plugins.
      */
+    @RequirePOST
     public void doInstall(StaplerRequest req, StaplerResponse rsp) throws IOException, ServletException {
         Jenkins.getInstance().checkPermission(Jenkins.ADMINISTER);
         Set<String> plugins = new LinkedHashSet<>();