Detailed analysis of a SQL injection vulnerability in early versions of the ThinkPHP framework

Detailed analysis of a SQL injection vulnerability in early versions of the ThinkPHP framework_PHP Tutorial

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Release： 2016-07-13 10:26:35

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There was an announcement on the ThinkPHP official website stating that there is a SQL injection vulnerability in ThinkPHP 3.1.3 and previous versions. The vulnerability exists in the ThinkPHP/Lib/Core/Model.class.php file
According to the official documentation, the method of "preventing SQL injection" is explained (refer to http://doc.thinkphp.cn/manual/sql_injection.html)
Using query condition preprocessing can prevent SQL injection. Yes, it can be effective when using the following code:

$Model->where("id=%d and username='%s' and xx='%f'",array($id,$username,$xx))->select();

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$Model->where("id=%d and username='%s' and xx='%f'",$id,$username,$xx)->select();

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However, when you use the following code, there is no "preventing SQL injection" effect (but the official document says that it can prevent SQL injection):

$model->query('select * from user where id=%d and status=%s',$id,$status);

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$model->query('select * from user where id=%d and status=%s',array($id,$status));

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Cause analysis:

The parseSql function in the ThinkPHP/Lib/Core/Model.class.php file does not implement SQL filtering.
Its original function is:

protected function parseSql($sql,$parse) {
// 分析表达式
if(true === $parse) {
  $options = $this->_parseOptions();
  $sql =  $this->db->parseSql($sql,$options);
}elseif(is_array($parse)){ // SQL预处理
  $sql = vsprintf($sql,$parse);
}else{
  $sql  =  strtr($sql,array('__TABLE__'=>$this->getTableName(),'__PREFIX__'=>C('DB_PREFIX')));
}
$this->db->setModel($this->name);
return $sql;
}

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Verification vulnerability (example):
Request address:

http://localhost/Main&#63;id=boo" or 1="1

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http://localhost/Main&#63;id=boo%22%20or%201=%221

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action code:

$model=M('Peipeidui');
$m=$model->query('select * from peipeidui where name="%s"',$_GET['id']);
dump($m);exit;

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or:

$model=M('Peipeidui');
$m=$model->query('select * from peipeidui where name="%s"',array($_GET['id']));
dump($m);exit;

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Result:

All data in table peipeidui is listed, and the SQL injection statement takes effect.

Solution:

The parseSql function can be modified to:

protected function parseSql($sql,$parse) {
// 分析表达式
if(true === $parse) {
  $options = $this->_parseOptions();
  $sql =  $this->db->parseSql($sql,$options);
}elseif(is_array($parse)){ // SQL预处理
  $parse = array_map(array($this->db,'escapeString'),$parse);//此行为新增代码
  $sql = vsprintf($sql,$parse);
}else{
  $sql  =  strtr($sql,array('__TABLE__'=>$this->getTableName(),'__PREFIX__'=>C('DB_PREFIX')));
}
$this->db->setModel($this->name);
return $sql;
}

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Summary:
1. Don’t rely too much on TP’s underlying SQL filtering. Programmers must do security checks
2. It is not recommended to use $_GET, $_POST directly