Insecure Password Storage Using MD5 Hash Algorithm in ThreadController.php

### Summary:
I found a security vulnerability in PHPWind's source code in the file `\phpwind\upload\src\applications\native\controller\ThreadController.php`. The code uses the MD5 hash algorithm to store user passwords, which is considered insecure.

### Vulnerability Description:
MD5 is an outdated and cryptographically insecure hashing algorithm. It is susceptible to brute-force attacks and collisions, which means attackers can easily reverse-engineer MD5 hashes to retrieve plaintext passwords.
```
if ($pwforum->foruminfo['password']) {//设置了版块访问密码
if (!$this->loginUser->isExists()) {
// $this->forwardAction('u/login/run', array('backurl' => WindUrlHelper::createUrl('bbs/cate/run', array('fid' => $fid))));
$this->showError('该版块为加密版块您需要先登录才能访问！');
} else if(!isset($_GET['password'])||empty($_GET['password'])){//提示输入密码
$data = array('page_info'=>array(),'user_info'=>array('uid'=>$this->uid,'isjoin'=>$forum_isjoin,'forum_login'=>0),'forum_info'=>'','threads_list'=>array());
$this->setOutput($data,'data');
$this->showMessage('NATIVE:data.success');
}elseif (Pw::getPwdCode($pwforum->foruminfo['password']) != Pw::getPwdCode(**md5($_GET['password']))**) {//密码错误
// $this->forwardAction('bbs/forum/password', array('fid' => $fid));
$data = array('page_info'=>array(),'user_info'=>array('uid'=>$this->uid,'isjoin'=>$forum_isjoin,'forum_login'=>1),'forum_info'=>'','threads_list'=>array());
$this->setOutput($data,'data');
$this->showMessage('NATIVE:data.success');
}
}
```

### Impact:
This vulnerability exposes user passwords to potential compromise and puts the security of the entire PHPWind application at risk.

### Recommendation:
I recommend updating the password storage mechanism to use a more secure hashing algorithm such as bcrypt, Argon2, or at least SHA-256 with a salt. These algorithms provide better protection against brute-force and collision attacks.

### Additional Information:
The issue is present in the `ThreadController.php` file in the source code of PHPWind.

Start with phpwind/upload/src/applications/native/controller/ThreadController.php and trace Pw::getPwdCode plus where the forum password is created and stored. Determine how a secure password hash can be introduced without breaking existing forum passwords, then verify correct and incorrect password access paths and any available security tests.

Written by the indexing model from the issue text.