Re: Re: Pretty mammoth security issue with safe_mode_exec
| From: | Adam Wright | Date: | Fri, 05 Jan 2001 12:48:38 +0000 |
| Subject: | Re: Re: Pretty mammoth security issue with safe_mode_exec | ||
| References: | 1 | Groups: | php.dev |
| Request: | Send a blank email to php-dev+get-43036@lists.php.net to get a copy of this message | ||
99.9999% sure. Try it and see.
adamw
----- Original Message -----
From: "Zeev Suraski" <zeev@zend.com>
To: "Adam Wright" <adam@elysium.ltd.uk>
Cc: "PHP Development" <php-dev@lists.php.net>
Sent: Friday, January 05, 2001 12:42 PM
Subject: [PHP-DEV] Re: Pretty mammoth security issue with safe_mode_exec
> At 14:11 5/1/2001, Adam Wright wrote:
> >If you have safe mode enabled, and have a safe mode exec directory,
here's
> >how you can execute binarys outside of your safe mode exec directory!
> >
> >Normally...
> >
> >system("../../../../../bin/cp blah blip");
> >
> >would fail (as .. is blocked in _Exec (standard/exec.c)
> >
> >However...
> >
> >system("\.\./\.\./\.\./\.\./\.\./bin/cp blah blip");
> >
> >will work fine! This is because the .. check was performed before the
> >php_escape_shell_cmd in exec.c!
>
> That's very very odd, because as far as system() (or any function for that
> matter) is concerned, ".." and "\.\." is exactly the same thing. At the
> scanner level, all the way down in the Zend Engine, it converts the bogus
> "\.\." string (which has illegal escapes) to "..".
>
> Are you sure this is the symptom exactly?
>
> Zeev
>
>
> --
> Zeev Suraski <zeev@zend.com>
> CTO & co-founder, Zend Technologies Ltd.
> http://www.zend.com/
>
>
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