From 96a988f7ec9c652cfa2fbf26da17fd7a9bf75a1f Mon Sep 17 00:00:00 2001
From: Brion Vibber <brion@users.mediawiki.org>
Date: Sat, 7 Jan 2006 21:44:10 +0000
Subject: [PATCH] * Protect against spoofing of X-Forwarded-For header

---
 RELEASE-NOTES           |  1 +
 includes/ProxyTools.php | 22 ++++++++++++++++++++--
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/RELEASE-NOTES b/RELEASE-NOTES
index 1b385fb6dc..9245c39ac3 100644
--- a/RELEASE-NOTES
+++ b/RELEASE-NOTES
@@ -412,6 +412,7 @@ fully support the editing toolbar, but was found to be too confusing.
   http://en.wikipedia.org/wiki/Windows_Metafile_vulnerability
 * (bug 4507) Adjust FULLPAGENAMEE escaping to standard form
 * Blocked users can no longer roll back, change the protection of, or delete/undelete pages
+* Protect against spoofing of X-Forwarded-For header
 
 
 === Caveats ===
diff --git a/includes/ProxyTools.php b/includes/ProxyTools.php
index 42e39a8de7..5818309bfb 100644
--- a/includes/ProxyTools.php
+++ b/includes/ProxyTools.php
@@ -6,6 +6,23 @@ if ( ! defined( 'MEDIAWIKI' ) )
  * @package MediaWiki
  */
 
+function wfGetForwardedFor() {
+	if( function_exists( 'apache_request_headers' ) ) {
+		// More reliable than $_SERVER due to case and -/_ folding
+		$set = apache_request_headers();
+		$index = 'X-Forwarded-For';
+	} else {
+		// Subject to spoofing with headers like X_Forwarded_For
+		$set = $_SERVER;
+		$index = 'HTTP_X_FORWARDED_FOR';
+	}
+	if( isset( $set[$index] ) ) {
+		return $set[$index];
+	} else {
+		return null;
+	}
+}
+
 /** Work out the IP address based on various globals */
 function wfGetIP() {
 	global $wgSquidServers, $wgSquidServersNoPurge, $wgIP;
@@ -30,8 +47,9 @@ function wfGetIP() {
 	$trustedProxies = array_flip( array_merge( $wgSquidServers, $wgSquidServersNoPurge ) );
 	if ( count( $trustedProxies ) ) {
 		# Append XFF on to $ipchain
-		if ( isset( $_SERVER['HTTP_X_FORWARDED_FOR'] ) ) {
-			$xff = array_map( 'trim', explode( ',', $_SERVER['HTTP_X_FORWARDED_FOR'] ) );
+		$forwardedFor = wfGetForwardedFor();
+		if ( isset( $forwardedFor ) ) {
+			$xff = array_map( 'trim', explode( ',', $forwardedFor ) );
 			$xff = array_reverse( $xff );
 			$ipchain = array_merge( $ipchain, $xff );
 		}
-- 
2.20.1