diff --git a/backend.php b/backend.php
index 1805ce360..2e4da500f 100644
--- a/backend.php
+++ b/backend.php
@@ -1,5 +1,5 @@
 <?php
-	set_include_path(get_include_path() . PATH_SEPARATOR . 
+	set_include_path(get_include_path() . PATH_SEPARATOR .
 		dirname(__FILE__) . "/include");
 
 	/* remove ill effects of magic quotes */
@@ -20,6 +20,11 @@
 	$op = $_REQUEST["op"];
 	@$method = $_REQUEST['subop'] ? $_REQUEST['subop'] : $_REQUEST["method"];
 
+	if (!$method)
+		$method = 'index';
+	else
+		$method = strtolower($method);
+
 	/* Public calls compatibility shim */
 
 	$public_calls = array("globalUpdateFeeds", "rss", "getUnread", "getProfiles", "share",
@@ -30,6 +35,11 @@
 		return;
 	}
 
+	$csrf_token = $_REQUEST['csrf_token'];
+
+	if (!$csrf_token)
+		error_log("[$op/$method] CSRF: [$csrf_token]\n", 3, "/tmp/csrf.log");
+
 	require_once "functions.php";
 	require_once "sessions.php";
 	require_once "sanity_check.php";
@@ -138,13 +148,17 @@
 		$handler = new $op($link, $_REQUEST);
 
 		if ($handler) {
-			if ($handler->before($method)) {
-				if ($method && method_exists($handler, $method)) {
-					$handler->$method();
-				} else if (method_exists($handler, 'index')) {
-					$handler->index();
+			if (validate_csrf($csrf_token) || $handler->csrf_ignore($method)) {
+				if ($handler->before($method)) {
+					if ($method && method_exists($handler, $method)) {
+						$handler->$method();
+					}
+					$handler->after();
+					return;
 				}
-				$handler->after();
+			} else {
+				header("Content-Type: text/plain");
+				print json_encode(array("error" => array("code" => 6)));
 				return;
 			}
 		}
diff --git a/classes/article.php b/classes/article.php
index 90ca129b9..30f0c7d10 100644
--- a/classes/article.php
+++ b/classes/article.php
@@ -1,6 +1,12 @@
 <?php
 class Article extends Protected_Handler {
 
+	function csrf_ignore($method) {
+		$csrf_ignored = array("redirect");
+
+		return array_search($method, $csrf_ignored) !== false;
+	}
+
 	function redirect() {
 		$id = db_escape_string($_REQUEST['id']);
 
diff --git a/classes/feeds.php b/classes/feeds.php
index 3626e9fbc..6b498ac00 100644
--- a/classes/feeds.php
+++ b/classes/feeds.php
@@ -1,6 +1,12 @@
 <?php
 class Feeds extends Protected_Handler {
 
+	function csrf_ignore($method) {
+		$csrf_ignored = array("index");
+
+		return array_search($method, $csrf_ignored) !== false;
+	}
+
 	private function feedlist_init_cat($cat_id, $hidden = false) {
 		$obj = array();
 		$cat_id = (int) $cat_id;
diff --git a/classes/handler.php b/classes/handler.php
index 53b52ea03..404b8306b 100644
--- a/classes/handler.php
+++ b/classes/handler.php
@@ -8,6 +8,10 @@ class Handler {
 		$this->args = $args;
 	}
 
+	function csrf_ignore($method) {
+		return true;
+	}
+
 	function before() {
 		return true;
 	}
diff --git a/classes/pref_feeds.php b/classes/pref_feeds.php
index 5df5eb939..b83abd789 100644
--- a/classes/pref_feeds.php
+++ b/classes/pref_feeds.php
@@ -1,5 +1,12 @@
 <?php
 class Pref_Feeds extends Protected_Handler {
+
+	function csrf_ignore($method) {
+		$csrf_ignored = array("index", "getfeedtree", "add", "editcats", "editfeed");
+
+		return array_search($method, $csrf_ignored) !== false;
+	}
+
 	function batch_edit_cbox($elem, $label = false) {
 		print "<input type=\"checkbox\" title=\"".__("Check to enable field")."\"
 			onchange=\"dijit.byId('feedEditDlg').toggleField(this, '$elem', '$label')\">";
diff --git a/classes/pref_filters.php b/classes/pref_filters.php
index d953a8d1d..4ab12410f 100644
--- a/classes/pref_filters.php
+++ b/classes/pref_filters.php
@@ -1,6 +1,12 @@
 <?php
 class Pref_Filters extends Protected_Handler {
 
+	function csrf_ignore($method) {
+		$csrf_ignored = array("index", "getfiltertree", "edit");
+
+		return array_search($method, $csrf_ignored) !== false;
+	}
+
 	function filter_test($filter_type, $reg_exp,
 			$action_id, $action_param, $filter_param, $inverse, $feed_id) {
 
diff --git a/classes/pref_instances.php b/classes/pref_instances.php
index 893d2b6bf..aae5bbafb 100644
--- a/classes/pref_instances.php
+++ b/classes/pref_instances.php
@@ -1,6 +1,12 @@
 <?php
 class Pref_Instances extends Protected_Handler {
 
+	function csrf_ignore($method) {
+		$csrf_ignored = array("index", "edit");
+
+		return array_search($method, $csrf_ignored) !== false;
+	}
+
 	function before() {
 		if (parent::before()) {
 			if ($_SESSION["access_level"] < 10) {
diff --git a/classes/pref_labels.php b/classes/pref_labels.php
index 0d60731f3..951ae45ed 100644
--- a/classes/pref_labels.php
+++ b/classes/pref_labels.php
@@ -1,6 +1,12 @@
 <?php
 class Pref_Labels extends Protected_Handler {
 
+	function csrf_ignore($method) {
+		$csrf_ignored = array("index", "getlabeltree", "edit");
+
+		return array_search($method, $csrf_ignored) !== false;
+	}
+
 	function edit() {
 		$label_id = db_escape_string($_REQUEST['id']);
 
diff --git a/classes/pref_prefs.php b/classes/pref_prefs.php
index 5a216d2b1..03e39caa5 100644
--- a/classes/pref_prefs.php
+++ b/classes/pref_prefs.php
@@ -1,6 +1,12 @@
 <?php
 class Pref_Prefs extends Protected_Handler {
 
+	function csrf_ignore($method) {
+		$csrf_ignored = array("index");
+
+		return array_search($method, $csrf_ignored) !== false;
+	}
+
 	function changepassword() {
 
 		$old_pw = $_POST["old_password"];
diff --git a/classes/pref_users.php b/classes/pref_users.php
index b9d162fd2..fe32ce14c 100644
--- a/classes/pref_users.php
+++ b/classes/pref_users.php
@@ -1,6 +1,5 @@
 <?php
 class Pref_Users extends Protected_Handler {
-
 		function before() {
 			if (parent::before()) {
 				if ($_SESSION["access_level"] < 10) {
@@ -12,6 +11,12 @@ class Pref_Users extends Protected_Handler {
 			return false;
 		}
 
+		function csrf_ignore($method) {
+			$csrf_ignored = array("index");
+
+			return array_search($method, $csrf_ignored) !== false;
+		}
+
 		function userdetails() {
 
 			header("Content-Type: text/xml");
diff --git a/classes/rpc.php b/classes/rpc.php
index 8145b0407..4cdaef935 100644
--- a/classes/rpc.php
+++ b/classes/rpc.php
@@ -1,6 +1,12 @@
 <?php
 class RPC extends Protected_Handler {
 
+	function csrf_ignore($method) {
+		$csrf_ignored = array("sanitycheck", "buttonplugin");
+
+		return array_search($method, $csrf_ignored) !== false;
+	}
+
 	function setprofile() {
 		$id = db_escape_string($_REQUEST["id"]);
 
diff --git a/include/functions.php b/include/functions.php
index e561d8e3d..ed28fd257 100644
--- a/include/functions.php
+++ b/include/functions.php
@@ -721,6 +721,7 @@
 				$_SESSION["uid"] = db_fetch_result($result, 0, "id");
 				$_SESSION["name"] = db_fetch_result($result, 0, "login");
 				$_SESSION["access_level"] = db_fetch_result($result, 0, "access_level");
+				$_SESSION["csrf_token"] = sha1(uniqid(rand(), true));
 
 				db_query($link, "UPDATE ttrss_users SET last_login = NOW() WHERE id = " .
 					$_SESSION["uid"]);
@@ -810,6 +811,10 @@
 		}
 	}
 
+	function validate_csrf($csrf_token) {
+		return $csrf_token == $_SESSION['csrf_token'];
+	}
+
 	function validate_session($link) {
 		if (SINGLE_USER_MODE) return true;
 
@@ -2064,6 +2069,8 @@
 
 		$params["collapsed_feedlist"] = (int) get_pref($link, "_COLLAPSED_FEEDLIST");
 
+		$params["csrf_token"] = $_SESSION["csrf_token"];
+
 		return $params;
 	}
 
diff --git a/js/functions.js b/js/functions.js
index 02134aafa..52201bd65 100644
--- a/js/functions.js
+++ b/js/functions.js
@@ -1,6 +1,25 @@
 var notify_silent = false;
 var loading_progress = 0;
 var sanity_check_done = false;
+var init_params = {};
+
+Ajax.Base.prototype.initialize = Ajax.Base.prototype.initialize.wrap(
+	function (callOriginal, options) {
+
+		if (getInitParam("csrf_token") != undefined) {
+			Object.extend(options, options || { });
+
+			if (Object.isString(options.parameters))
+				options.parameters = options.parameters.toQueryParams();
+			else if (Object.isHash(options.parameters))
+				options.parameters = options.parameters.toObject();
+
+			options.parameters["csrf_token"] = getInitParam("csrf_token");
+		}
+
+		return callOriginal(options);
+	}
+);
 
 /* add method to remove element from array */
 
diff --git a/js/tt-rss.js b/js/tt-rss.js
index 084a21863..4f82545f9 100644
--- a/js/tt-rss.js
+++ b/js/tt-rss.js
@@ -5,7 +5,6 @@ var _active_feed_id = 0;
 var _active_feed_is_cat = false;
 var hotkey_prefix = false;
 var hotkey_prefix_pressed = false;
-var init_params = {};
 var _force_scheduled_update = false;
 var last_scheduled_update = false;