From dadffe89897edc8df049d8f5251e3ee3ec26af1b Mon Sep 17 00:00:00 2001
From: Paul Holden <paulh@moodle.com>
Date: Tue, 27 Feb 2024 21:29:36 +0000
Subject: [PATCH] MDL-80878 tool_mfa: safely retrieve the referrer URL.

---
 admin/tool/mfa/index.php | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/admin/tool/mfa/index.php b/admin/tool/mfa/index.php
index eef7f07ffd2..a7bac9c3bab 100644
--- a/admin/tool/mfa/index.php
+++ b/admin/tool/mfa/index.php
@@ -31,8 +31,7 @@ require_once($CFG->libdir.'/tablelib.php');
 require_login(null, false);
 require_capability('moodle/site:config', context_system::instance());
 
-global $_SERVER;
-$returnurl = $_SERVER['HTTP_REFERER'];
+$returnurl = get_local_referer(false);
 
 $PAGE->set_url('/admin/tool/mfa/index.php');