From 9f2275ba8099ba8c9d9b5b45231c9844d6dedaf2 Mon Sep 17 00:00:00 2001
From: Janusz Dobrowolski <janusz@frontaccouting.eu>
Date: Wed, 25 May 2011 10:16:40 +0200
Subject: [PATCH] Added CSRF attack prevention on password change.

---
 admin/change_current_user_password.php |  2 +-
 includes/ui/ui_controls.inc            | 20 ++++++++++++++++++--
 2 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/admin/change_current_user_password.php b/admin/change_current_user_password.php
index 247517a2..4ed37fb0 100644
--- a/admin/change_current_user_password.php
+++ b/admin/change_current_user_password.php
@@ -47,7 +47,7 @@ function can_process()
 	return true;
 }
 
-if (isset($_POST['UPDATE_ITEM']))
+if (isset($_POST['UPDATE_ITEM']) && check_csrf_token())
 {
 
 	if (can_process())
diff --git a/includes/ui/ui_controls.inc b/includes/ui/ui_controls.inc
index 6d0ccf99..8687b336 100644
--- a/includes/ui/ui_controls.inc
+++ b/includes/ui/ui_controls.inc
@@ -53,11 +53,27 @@ function start_form($multi=false, $dummy=false, $action="", $name="")
 
 function end_form($breaks=0)
 {
+	global $Ajax;
+
+	$_SESSION['csrf_token'] = hash('sha256', uniqid(mt_rand(), true));
 	if ($breaks)
 		br($breaks);
-	echo "<input type=\"hidden\" name=\"_focus\" value=\"".get_post('_focus')."\">\n";
-	echo "<input type=\"hidden\" name=\"_modified\" value=\"".get_post('_modified', 0)."\">\n";
+	hidden('_focus');
+	hidden('_modified', get_post('_modified', 0));
+	hidden('_token', $_SESSION['csrf_token']);
 	echo "</form>\n";
+	$Ajax->activate('token');
+}
+
+function check_csrf_token()
+{
+	if ($_SESSION['csrf_token'] != @$_POST['_token'])
+	{
+		display_error(_("Request from outside of this page is forbidden."));
+		error_log(_("CSRF attack detected from: ").@$_SERVER['HTTP_HOST'].' ('.@$_SERVER['HTTP_REFERER'].')');
+		return false;
+	}
+	return true;
 }
 
 function start_table($class=false, $extra="", $padding='2', $spacing='0')
-- 
2.30.2