Commit message: None
CVE: CVE-2016-3141
CWE: CWE-119
Vulnerability description: Use-after-free vulnerability in wddx.c in the WDDX extension in PHP before 5.5.33 and 5.6.x before 5.6.19 allows remote attackers to cause a denial of service (memory corruption and application crash) or possibly have unspecified other impact by triggering a wddx_deserialize call on XML data containing a crafted var element.

Project: php

void php_wddx_packet_start(wddx_packet *packet, char *comment, int comment_len)
{
	php_wddx_add_chunk_static(packet, WDDX_PACKET_S);
	if (comment) {
		php_wddx_add_chunk_static(packet, WDDX_HEADER_S);
		php_wddx_add_chunk_static(packet, WDDX_COMMENT_S);
		php_wddx_add_chunk_ex(packet, comment, comment_len);
		php_wddx_add_chunk_static(packet, WDDX_COMMENT_E);
		php_wddx_add_chunk_static(packet, WDDX_HEADER_E);
	} else {
		php_wddx_add_chunk_static(packet, WDDX_HEADER);
	}
	php_wddx_add_chunk_static(packet, WDDX_DATA_S);
}

Project: php

static void php_wddx_push_element(void *user_data, const XML_Char *name, const XML_Char **atts)
{
	st_entry ent;
	wddx_stack *stack = (wddx_stack *)user_data;

	if (!strcmp(name, EL_PACKET)) {
		int i;

		if (atts) for (i=0; atts[i]; i++) {
			if (!strcmp(atts[i], EL_VERSION)) {
				/* nothing for now */
			}
		}
	} else if (!strcmp(name, EL_STRING)) {
		ent.type = ST_STRING;
		SET_STACK_VARNAME;

		ALLOC_ZVAL(ent.data);
		INIT_PZVAL(ent.data);
		Z_TYPE_P(ent.data) = IS_STRING;
		Z_STRVAL_P(ent.data) = STR_EMPTY_ALLOC();
		Z_STRLEN_P(ent.data) = 0;
		wddx_stack_push((wddx_stack *)stack, &ent, sizeof(st_entry));
	} else if (!strcmp(name, EL_BINARY)) {
		ent.type = ST_BINARY;
		SET_STACK_VARNAME;

		ALLOC_ZVAL(ent.data);
		INIT_PZVAL(ent.data);
		Z_TYPE_P(ent.data) = IS_STRING;
		Z_STRVAL_P(ent.data) = STR_EMPTY_ALLOC();
		Z_STRLEN_P(ent.data) = 0;
		wddx_stack_push((wddx_stack *)stack, &ent, sizeof(st_entry));
	} else if (!strcmp(name, EL_CHAR)) {
		int i;

		if (atts) for (i = 0; atts[i]; i++) {
			if (!strcmp(atts[i], EL_CHAR_CODE) && atts[++i] && atts[i][0]) {
				char tmp_buf[2];

				snprintf(tmp_buf, sizeof(tmp_buf), "%c", (char)strtol(atts[i], NULL, 16));
				php_wddx_process_data(user_data, tmp_buf, strlen(tmp_buf));
				break;
			}
		}
	} else if (!strcmp(name, EL_NUMBER)) {
		ent.type = ST_NUMBER;
		SET_STACK_VARNAME;

		ALLOC_ZVAL(ent.data);
		INIT_PZVAL(ent.data);
		Z_TYPE_P(ent.data) = IS_LONG;
		Z_LVAL_P(ent.data) = 0;
		wddx_stack_push((wddx_stack *)stack, &ent, sizeof(st_entry));
	} else if (!strcmp(name, EL_BOOLEAN)) {
		int i;

		if (atts) for (i = 0; atts[i]; i++) {
			if (!strcmp(atts[i], EL_VALUE) && atts[++i] && atts[i][0]) {
				ent.type = ST_BOOLEAN;
				SET_STACK_VARNAME;

				ALLOC_ZVAL(ent.data);
				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]));
				break;
			}
		}
	} else if (!strcmp(name, EL_NULL)) {
		ent.type = ST_NULL;
		SET_STACK_VARNAME;

		ALLOC_ZVAL(ent.data);
		INIT_PZVAL(ent.data);
		ZVAL_NULL(ent.data);

		wddx_stack_push((wddx_stack *)stack, &ent, sizeof(st_entry));
	} else if (!strcmp(name, EL_ARRAY)) {
		ent.type = ST_ARRAY;
		SET_STACK_VARNAME;

		ALLOC_ZVAL(ent.data);
		array_init(ent.data);
		INIT_PZVAL(ent.data);
		wddx_stack_push((wddx_stack *)stack, &ent, sizeof(st_entry));
	} else if (!strcmp(name, EL_STRUCT)) {
		ent.type = ST_STRUCT;
		SET_STACK_VARNAME;

		ALLOC_ZVAL(ent.data);
		array_init(ent.data);
		INIT_PZVAL(ent.data);
		wddx_stack_push((wddx_stack *)stack, &ent, sizeof(st_entry));
	} else if (!strcmp(name, EL_VAR)) {
		int i;

		if (atts) for (i = 0; atts[i]; i++) {
			if (!strcmp(atts[i], EL_NAME) && atts[++i] && atts[i][0]) {
				stack->varname = estrdup(atts[i]);
				break;
			}
		}
	} else if (!strcmp(name, EL_RECORDSET)) {
		int i;

		ent.type = ST_RECORDSET;
		SET_STACK_VARNAME;
		MAKE_STD_ZVAL(ent.data);
		array_init(ent.data);

		if (atts) for (i = 0; atts[i]; i++) {
			if (!strcmp(atts[i], "fieldNames") && atts[++i] && atts[i][0]) {
				zval *tmp;
				char *key;
				char *p1, *p2, *endp;

				endp = (char *)atts[i] + strlen(atts[i]);
				p1 = (char *)atts[i];
				while ((p2 = php_memnstr(p1, ",", sizeof(",")-1, endp)) != NULL) {
					key = estrndup(p1, p2 - p1);
					MAKE_STD_ZVAL(tmp);
					array_init(tmp);
					add_assoc_zval_ex(ent.data, key, p2 - p1 + 1, tmp);
					p1 = p2 + sizeof(",")-1;
					efree(key);
				}

				if (p1 <= endp) {
					MAKE_STD_ZVAL(tmp);
					array_init(tmp);
					add_assoc_zval_ex(ent.data, p1, endp - p1 + 1, tmp);
				}

				break;
			}
		}

		wddx_stack_push((wddx_stack *)stack, &ent, sizeof(st_entry));
	} else if (!strcmp(name, EL_FIELD)) {
		int i;
		st_entry ent;

		ent.type = ST_FIELD;
		ent.varname = NULL;
		ent.data = NULL;

		if (atts) for (i = 0; atts[i]; i++) {
			if (!strcmp(atts[i], EL_NAME) && atts[++i] && atts[i][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) {
					ent.data = *field;
				}

				break;
			}
		}

		wddx_stack_push((wddx_stack *)stack, &ent, sizeof(st_entry));
	} else if (!strcmp(name, EL_DATETIME)) {
		ent.type = ST_DATETIME;
		SET_STACK_VARNAME;

		ALLOC_ZVAL(ent.data);
		INIT_PZVAL(ent.data);
		Z_TYPE_P(ent.data) = IS_LONG;
		wddx_stack_push((wddx_stack *)stack, &ent, sizeof(st_entry));
	}
}

Project: php

static void php_wddx_serialize_string(wddx_packet *packet, zval *var TSRMLS_DC)
{
	php_wddx_add_chunk_static(packet, WDDX_STRING_S);

	if (Z_STRLEN_P(var) > 0) {
		char *buf;
		size_t buf_len;

		buf = php_escape_html_entities(Z_STRVAL_P(var), Z_STRLEN_P(var), &buf_len, 0, ENT_QUOTES, NULL TSRMLS_CC);

		php_wddx_add_chunk_ex(packet, buf, buf_len);

		efree(buf);
	}
	php_wddx_add_chunk_static(packet, WDDX_STRING_E);
}

Project: php

void php_wddx_serialize_var(wddx_packet *packet, zval *var, char *name, int name_len TSRMLS_DC)
{
	HashTable *ht;

	if (name) {
		size_t name_esc_len;
		char *tmp_buf, *name_esc;

		name_esc = php_escape_html_entities(name, name_len, &name_esc_len, 0, ENT_QUOTES, NULL TSRMLS_CC);
		tmp_buf = emalloc(name_esc_len + sizeof(WDDX_VAR_S));
		snprintf(tmp_buf, name_esc_len + sizeof(WDDX_VAR_S), WDDX_VAR_S, name_esc);
		php_wddx_add_chunk(packet, tmp_buf);
		efree(tmp_buf);
		efree(name_esc);
	}

	switch(Z_TYPE_P(var)) {
		case IS_STRING:
			php_wddx_serialize_string(packet, var TSRMLS_CC);
			break;

		case IS_LONG:
		case IS_DOUBLE:
			php_wddx_serialize_number(packet, var);
			break;

		case IS_BOOL:
			php_wddx_serialize_boolean(packet, var);
			break;

		case IS_NULL:
			php_wddx_serialize_unset(packet);
			break;

		case IS_ARRAY:
			ht = Z_ARRVAL_P(var);
			if (ht->nApplyCount > 1) {
				php_error_docref(NULL TSRMLS_CC, E_RECOVERABLE_ERROR, "WDDX doesn't support circular references");
				return;
			}
			ht->nApplyCount++;
			php_wddx_serialize_array(packet, var);
			ht->nApplyCount--;
			break;

		case IS_OBJECT:
			ht = Z_OBJPROP_P(var);
			if (ht->nApplyCount > 1) {
				php_error_docref(NULL TSRMLS_CC, E_RECOVERABLE_ERROR, "WDDX doesn't support circular references");
				return;
			}
			ht->nApplyCount++;
 			php_wddx_serialize_object(packet, var);
			ht->nApplyCount--;
			break;
	}

	if (name) {
		php_wddx_add_chunk_static(packet, WDDX_VAR_E);
	}
}