full-disclosure - Re: Apache 2.2.17 exploit?

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Date: Tue, 04 Oct 2011 22:13:35 +0000
From: halfdog <me@...fdog.net>
To: Kai <kai@...nn.net>
Cc: full-disclosure@...ts.grok.org.uk
Subject: Re: Apache 2.2.17 exploit?

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halfdog wrote:
> Hello Kai, Kai wrote:
>> Hi halfdog,
> 
>>> Just for those, who want to build their own apache shell code 
>>> for testing purposes, this snip might be of some use. ...
> 
>> wasn't that bug fixed a long ago? 
>> https://bugs.php.net/bug.php?id=38915 ---> 
>> https://issues.apache.org/bugzilla/show_bug.cgi?id=46425 sorry if
>> i'm talking about different thing.
> 
> Thanks for the link. I have to look into it closer, perhaps my
> code is just working because I dup2 the fd to stdin before exec,
> which might get rid of the FD_CLOEXEC. At least in tests, where I 
> injected code into mpm-worker on x86 (32bit) using gdb and other 
> methods, it succeeded in giving me remote shell.

Yes, it's the the dup2 that does the trick:

man:   dup, dup2 - duplicate a file descriptor

The two descriptors do not share file descriptor flags  (the
close-on-exec flag). The close-on-exec flag (FD_CLOEXEC; see fcntl(2))
for the duplicate descriptor is off.

That is why, the tcp-sock fd stays alive after execv("/bin/sh", ...)

hd

http://www.halfdog.net/
PGP: 156A AE98 B91F 0114 FE88  2BD8 C459 9386 feed a bee
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