CVE-2016-7418 (published 2016-09-17T21:59Z)

The php_wddx_push_element function in ext/wddx/wddx.c in PHP before 5.6.26 and 7.x before 7.0.11 allows remote attackers to cause a denial of service (invalid pointer access and out-of-bounds read) or possibly have unspecified other impact via an incorrect boolean element in a wddxPacket XML document, leading to mishandling in a wddx_deserialize call.

Severity: MEDIUM
CVSS v2 base score: 5.0 (AV:N/AC:L/Au:N/C:N/I:N/A:P)
CVSS v3 base score: 7.5, HIGH (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)

Weakness information:
cwe_id: CWE-119
cwe_name: Improper Restriction of Operations within the Bounds of a Memory Buffer
description: The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.
extended_description: 
            Certain languages allow direct addressing of memory locations and do not automatically ensure that these locations are valid for the memory buffer that is being referenced. This can cause read or write operations to be performed on memory locations that may be associated with other variables, data structures, or internal program data.
         
         

Fix information:
repo_url: https://github.com/php/php-src
commit_details: repo_url: https://github.com/php/php-src
author: Stanislav Malyshev
author_date: 2016-09-12 00:35:01-07:00
msg: Fix bug #73065: Out-Of-Bounds Read in php_wddx_push_element of wddx.c
repository: repo_url: https://github.com/php/php-src
repo_name: php/php-src
description: The PHP Interpreter
repo_language: C
owner: php
file_changes: filename: bug73065.phpt
change_type: ModificationType.ADD
diff: @@ -0,0 +1,98 @@
+--TEST--
+Bug #73065: Out-Of-Bounds Read in php_wddx_push_element of wddx.c
+--SKIPIF--
+<?php
+if (!extension_loaded('wddx')) {
+    die('skip. wddx not available');
+}
+?>
+--FILE--
+<?php
+
+$xml1 = <<<XML
+<?xml version='1.0' ?>
+    <!DOCTYPE et SYSTEM 'w'>
+    <wddxPacket ven='1.0'>
+        <array>
+            <var Name="name">
+                <boolean value="keliu"></boolean>
+            </var>
+            <var name="1111">
+                <var name="2222">
+                    <var name="3333"></var>
+                </var>
+            </var>
+        </array>
+    </wddxPacket>
+XML;
+    
+$xml2 = <<<XML
+<?xml version='1.0' ?>
+    <!DOCTYPE et SYSTEM 'w'>
+    <wddxPacket ven='1.0'>
+        <array>
+            <char Name="code">
+                <boolean value="keliu"></boolean>
+            </char>
+        </array>
+    </wddxPacket>
+XML;
+
+$xml3 = <<<XML
+<?xml version='1.0' ?>
+    <!DOCTYPE et SYSTEM 'w'>
+    <wddxPacket ven='1.0'>
+        <array>
+            <boolean Name="value">
+                <boolean value="keliu"></boolean>
+            </boolean>
+        </array>
+    </wddxPacket>
+XML;
+
+$xml4 = <<<XML
+<?xml version='1.0' ?>
+    <!DOCTYPE et SYSTEM 'w'>
+    <wddxPacket ven='1.0'>
+        <array>
+            <recordset Name="fieldNames">
+                <boolean value="keliu"></boolean>
+            </recordset>
+        </array>
+    </wddxPacket>
+XML;
+
+$xml5 = <<<XML
+<?xml version='1.0' ?>
+    <!DOCTYPE et SYSTEM 'w'>
+    <wddxPacket ven='1.0'>
+        <array>
+            <field Name="name">
+                <boolean value="keliu"></boolean>
+            </field>
+        </array>
+    </wddxPacket>
+XML;
+
+for($i=1;$i<=5;$i++) {
+	$xmlvar = "xml$i";
+    $array = wddx_deserialize($$xmlvar);
+    var_dump($array);
+}
+?>
+DONE
+--EXPECTF--
+array(0) {
+}
+array(0) {
+}
+array(0) {
+}
+array(1) {
+  [0]=>
+  array(0) {
+  }
+}
+array(0) {
+}
+DONE
\ No newline at end of file

programming_language: HTML
filename: wddx.c
change_type: ModificationType.MODIFY
diff: @@ -780,10 +780,10 @@ static void php_wddx_push_element(void *user_data, const XML_Char *name, const X
 		int i;
 
 		if (atts) for (i = 0; atts[i]; i++) {
-			if (!strcmp(atts[i], EL_CHAR_CODE) && atts[++i] && atts[i][0]) {
+			if (!strcmp(atts[i], EL_CHAR_CODE) && atts[i+1] && atts[i+1][0]) {
 				char tmp_buf[2];
 
-				snprintf(tmp_buf, sizeof(tmp_buf), "%c", (char)strtol(atts[i], NULL, 16));
+				snprintf(tmp_buf, sizeof(tmp_buf), "%c", (char)strtol(atts[i+1], NULL, 16));
 				php_wddx_process_data(user_data, tmp_buf, strlen(tmp_buf));
 				break;
 			}
@@ -801,7 +801,7 @@ static void php_wddx_push_element(void *user_data, const XML_Char *name, const X
 		int i;
 
 		if (atts) for (i = 0; atts[i]; i++) {
-			if (!strcmp(atts[i], EL_VALUE) && atts[++i] && atts[i][0]) {
+			if (!strcmp(atts[i], EL_VALUE) && atts[i+1] && atts[i+1][0]) {
 				ent.type = ST_BOOLEAN;
 				SET_STACK_VARNAME;
 
@@ -809,7 +809,7 @@ static void php_wddx_push_element(void *user_data, const XML_Char *name, const X
 				INIT_PZVAL(ent.data);
 				Z_TYPE_P(ent.data) = IS_BOOL;
 				wddx_stack_push((wddx_stack *)stack, &ent, sizeof(st_entry));
-				php_wddx_process_data(user_data, atts[i], strlen(atts[i]));
+				php_wddx_process_data(user_data, atts[i+1], strlen(atts[i+1]));
 				break;
 			}
 		}
@@ -842,9 +842,9 @@ static void php_wddx_push_element(void *user_data, const XML_Char *name, const X
 		int i;
 
 		if (atts) for (i = 0; atts[i]; i++) {
-			if (!strcmp(atts[i], EL_NAME) && atts[++i] && atts[i][0]) {
+			if (!strcmp(atts[i], EL_NAME) && atts[i+1] && atts[i+1][0]) {
 				if (stack->varname) efree(stack->varname);
-				stack->varname = estrdup(atts[i]);
+				stack->varname = estrdup(atts[i+1]);
 				break;
 			}
 		}
@@ -857,11 +857,12 @@ static void php_wddx_push_element(void *user_data, const XML_Char *name, const X
 		array_init(ent.data);
 
 		if (atts) for (i = 0; atts[i]; i++) {
-			if (!strcmp(atts[i], "fieldNames") && atts[++i] && atts[i][0]) {
+			if (!strcmp(atts[i], "fieldNames") && atts[i+1] && atts[i+1][0]) {
 				zval *tmp;
 				char *key;
 				char *p1, *p2, *endp;
 
+				i++;
 				endp = (char *)atts[i] + strlen(atts[i]);
 				p1 = (char *)atts[i];
 				while ((p2 = php_memnstr(p1, ",", sizeof(",")-1, endp)) != NULL) {
@@ -893,13 +894,13 @@ static void php_wddx_push_element(void *user_data, const XML_Char *name, const X
 		ent.data = NULL;
 
 		if (atts) for (i = 0; atts[i]; i++) {
-			if (!strcmp(atts[i], EL_NAME) && atts[++i] && atts[i][0]) {
+			if (!strcmp(atts[i], EL_NAME) && atts[i+1] && atts[i+1][0]) {
 				st_entry *recordset;
 				zval **field;
 
 				if (wddx_stack_top(stack, (void**)&recordset) == SUCCESS &&
 					recordset->type == ST_RECORDSET &&
-					zend_hash_find(Z_ARRVAL_P(recordset->data), (char*)atts[i], strlen(atts[i])+1, (void**)&field) == SUCCESS) {
+					zend_hash_find(Z_ARRVAL_P(recordset->data), (char*)atts[i+1], strlen(atts[i+1])+1, (void**)&field) == SUCCESS) {
 					ent.data = *field;
 				}
 

programming_language: C