Fix CVE-2010-0397: null pointer dereference when processing invalid XML-RPC

requests (bug #51288)

Author: rgeissert

NEWS

@@ -6,6 +6,9 @@ PHP                                                                        NEWS
 - Added stream filter support to mcrypt extension (ported from 
   mcrypt_filter). (Stas)
 
+- Fixed a NULL pointer dereference when processing invalid XML-RPC
+  requests (Fixes CVE-2010-0397, bug #51288). (Raphael Geissert)
+
 - Fixed bug #51269 (zlib.output_compression Overwrites Vary Header). (Adam)
 - Fixed bug #51257 (CURL_VERSION_LARGEFILE incorrectly used after libcurl
   version 7.10.1). (aron dot ujvari at microsec dot hu)

ext/xmlrpc/tests/bug51288.phpt

@@ -0,0 +1,14 @@
+--TEST--
+Bug #51288 (CVE-2010-0397, NULL pointer deref when no <methodName> in request)
+--FILE--
+<?php
+$method = NULL;
+$req = '<?xml version="1.0"?><methodCall></methodCall>';
+var_dump(xmlrpc_decode_request($req, $method));
+var_dump($method);
+echo "Done\n";
+?>
+--EXPECT--
+NULL
+NULL
+Done

ext/xmlrpc/xmlrpc-epi-php.c

@@ -778,6 +778,7 @@ zval* decode_request_worker(char *xml_in, int xml_in_len, char *encoding_in, zva
 	zval* retval = NULL;
 	XMLRPC_REQUEST response;
 	STRUCT_XMLRPC_REQUEST_INPUT_OPTIONS opts = {{0}};
+	const char *method_name;
 	opts.xml_elem_opts.encoding = encoding_in ? utf8_get_encoding_id_from_string(encoding_in) : ENCODING_DEFAULT;
 
 	/* generate XMLRPC_REQUEST from raw xml */
@@ -788,10 +789,15 @@ zval* decode_request_worker(char *xml_in, int xml_in_len, char *encoding_in, zva
 
 		if (XMLRPC_RequestGetRequestType(response) == xmlrpc_request_call) {
 			if (method_name_out) {
-				zval_dtor(method_name_out);
-				Z_TYPE_P(method_name_out) = IS_STRING;
-				Z_STRVAL_P(method_name_out) = estrdup(XMLRPC_RequestGetMethodName(response));
-				Z_STRLEN_P(method_name_out) = strlen(Z_STRVAL_P(method_name_out));
+				method_name = XMLRPC_RequestGetMethodName(response);
+				if (method_name) {
+					zval_dtor(method_name_out);
+					Z_TYPE_P(method_name_out) = IS_STRING;
+					Z_STRVAL_P(method_name_out) = estrdup(method_name);
+					Z_STRLEN_P(method_name_out) = strlen(Z_STRVAL_P(method_name_out));
+				} else {
+					retval = NULL;
+				}
 			}
 		}