From php community:

BUG: https://bugs.php.net/bug.php?id=68710

CODE: https://github.com/php/php-src/commit/b585a3aed7880a5fa5c18e2b838fc96f40e075bd

Created for php 5.3 based on code from the community bug.

--- php-5.3.29/ext/standard/var_unserializer.c_orig	2015-06-03 16:10:58.649025322 -0700

+++ php-5.3.29/ext/standard/var_unserializer.c	2015-06-03 16:11:38.093987868 -0700

@@ -298,7 +298,7 @@

 		} else {

 			/* object properties should include no integers */

 			convert_to_string(key);

-			if (zend_symtable_find(ht, Z_STRVAL_P(key), Z_STRLEN_P(key) + 1, (void **)&old_data)==SUCCESS) {

+			if (zend_hash_find(ht, Z_STRVAL_P(key), Z_STRLEN_P(key) + 1, (void **)&old_data)==SUCCESS) {

 				var_push_dtor(var_hash, old_data);

 			}

 			zend_hash_update(ht, Z_STRVAL_P(key), Z_STRLEN_P(key) + 1, &data,

--- php-5.3.29/ext/standard/var_unserializer.re_orig	2015-06-03 16:09:21.637872795 -0700

+++ php-5.3.29/ext/standard/var_unserializer.re	2015-06-03 16:10:05.641543642 -0700

@@ -304,7 +304,7 @@

 		} else {

 			/* object properties should include no integers */

 			convert_to_string(key);

-			if (zend_symtable_find(ht, Z_STRVAL_P(key), Z_STRLEN_P(key) + 1, (void **)&old_data)==SUCCESS) {

+			if (zend_hash_find(ht, Z_STRVAL_P(key), Z_STRLEN_P(key) + 1, (void **)&old_data)==SUCCESS) {

 				var_push_dtor(var_hash, old_data);

 			}

 			zend_hash_update(ht, Z_STRVAL_P(key), Z_STRLEN_P(key) + 1, &data,

--- php-5.3.29/ext/standard/tests/strings/bug68710.phpt_orig	2015-06-03 16:16:50.728789966 -0700

+++ php-5.3.29/ext/standard/tests/strings/bug68710.phpt	2015-06-03 16:12:43.728868416 -0700

@@ -0,0 +1,25 @@

+--TEST--

+Bug #68710 Use after free vulnerability in unserialize() (bypassing the

+CVE-2014-8142 fix)

+--FILE--

+<?php

+for ($i=4; $i<100; $i++) {

+ $m = new StdClass();

+

+ $u = array(1);

+

+ $m->aaa = array(1,2,&$u,4,5);

+ $m->bbb = 1;

+ $m->ccc = &$u;

+ $m->ddd = str_repeat("A", $i);

+

+ $z = serialize($m);

+ $z = str_replace("aaa", "123", $z);

+ $z = str_replace("bbb", "123", $z);

+ $y = unserialize($z);

+ $z = serialize($y);

+}

+?>

+===DONE===

+--EXPECTF--

+===DONE===