Changeset 24916

Timestamp:

07/31/2013 06:46:02 AM (11 years ago)

Author:

nacin

Message:

Additional checks when evaluating the safety of an HTTP request, to avoid false negatives.

Merges [24915] to the 3.6 branch.
fixes #24646.

Location:

branches/3.6

Files:

• . (modified) (1 prop)
• wp-includes/default-filters.php (modified) (1 diff)
• wp-includes/http.php (modified) (2 diffs)
• wp-includes/ms-default-filters.php (modified) (1 diff)

branches/3.6/wp-includes/default-filters.php

@@ -196 +196 @@
 add_filter( 'pingback_ping_source_uri', 'pingback_ping_source_uri'            );
 add_filter( 'xmlrpc_pingback_error',    'xmlrpc_pingback_error'               );
+
+add_filter( 'http_request_host_is_external', 'allowed_http_request_hosts', 10, 2 );
 
 // Actions

branches/3.6/wp-includes/http.php

@@ -452 +452 @@
         }
         if ( $ip ) {
-            if ( '127.0.0.1' === $ip )
-                return false;
             $parts = array_map( 'intval', explode( '.', $ip ) );
-            if ( 10 === $parts[0] )
-                return false;
-            if ( 172 === $parts[0] && 16 <= $parts[1] && 31 >= $parts[1] )
-                return false;
-            if ( 192 === $parts[0] && 168 === $parts[1] )
-                return false;
+            if ( '127.0.0.1' === $ip
+                || ( 10 === $parts[0] )
+                || ( 172 === $parts[0] && 16 <= $parts[1] && 31 >= $parts[1] )
+                || ( 192 === $parts[0] && 168 === $parts[1] )
+            ) {
+                // If host appears local, reject unless specifically allowed.
+                if ( ! apply_filters( 'http_request_host_is_external', false, $host, $url ) )
+                    return false;
+            }
         }
     }
@@ -476 +477 @@
     return false;
 }
+
+/**
+ * Whitelists allowed redirect hosts for safe HTTP requests as well.
+ *
+ * Attached to the http_request_host_is_external filter.
+ *
+ * @since 3.6.0
+ *
+ * @param bool $is_external
+ * @param string $host
+ * @return bool
+ */
+function allowed_http_request_hosts( $is_external, $host ) {
+    if ( ! $is_external && wp_validate_redirect( 'http://' . $host ) )
+        $is_external = true;
+    return $is_external;
+}
+
+/**
+ * Whitelists any domain in a multisite installation for safe HTTP requests.
+ *
+ * Attached to the http_request_host_is_external filter.
+ *
+ * @since 3.6.0
+ *
+ * @param bool $is_external
+ * @param string $host
+ * @return bool
+ */
+function ms_allowed_http_request_hosts( $is_external, $host ) {
+    global $wpdb, $current_site;
+    static $queried = array();
+    if ( $is_external )
+        return $is_external;
+    if ( $host === $current_site->domain )
+        return true;
+    if ( isset( $queried[ $host ] ) )
+        return $queried[ $host ];
+    $queried[ $host ] = (bool) $wpdb->get_var( $wpdb->prepare( "SELECT domain FROM $wpdb->blogs WHERE domain = %s LIMIT 1", $host ) );
+    return $queried[ $host ];
+}

branches/3.6/wp-includes/ms-default-filters.php

@@ -65 +65 @@
 // If the network upgrade hasn't run yet, assume ms-files.php rewriting is used.
 add_filter( 'default_site_option_ms_files_rewriting', '__return_true' );
+
+// Whitelist multisite domains for HTTP requests
+add_filter( 'http_request_host_is_external', 'ms_allowed_http_request_hosts', 20, 2 );