【安全预警】关于ThinkPHP 多个版本远程代码执行漏洞安全预警

5.1.x系列，编辑 library/think/Request.php 文件， 查找如下内容:
$this->method    = strtoupper($_POST[$this->config['var_method']]);
$method          = strtolower($this->method);
$this->{$method} = $_POST;
修改为:
$method = strtoupper($_POST[Config::get('var_method')]);
if (in_array($method, ['GET', 'POST', 'DELETE', 'PUT', 'PATCH'])) {
$method          = strtolower($this->method);
$this->{$method} = $_POST;
}

5.2.x系列，编辑 src/think/Request.php文件， 查找:
$this->method = strtoupper($_POST[$this->config['var_method']]);
$method       = strtolower($this->method);
unset($_POST[$this->config['var_method']]);
$this->{$method} = $_POST;
修改为:
$this->method = strtoupper($_POST[$this->config['var_method']]);
$method       = strtolower($this->method);

if (in_array($method, ['GET', 'POST', 'DELETE', 'PUT', 'PATCH'])) {
unset($_POST[$this->config['var_method']]);
$this->{$method} = $_POST;

}