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Date: Wed, 13 Jul 2011 17:23:58 -0400 (EDT)
From: "Steven M. Christey" <coley@...-smtp.mitre.org>
To: oss-security@...ts.openwall.com
Subject: Re: Apache symlink issue: can documented behavior be
 a security problem and hence get a CVE?


Very rarely, we will cover "documented behavior" if there is sufficient 
evidence of widespread abuse/misuse of that behavior by admins, in which 
case the CVE description would emphasize the fact that it is the admin's 
"fault" or "misconception."  I generally try to stay away from edge cases 
(such as this one) that could have a "snowball effect" of setting a 
precedent that could ultimately be used to argue for assigning too many 
low-priority CVEs to many issues.  I would be inclined to avoid assigning 
a CVE for this issue unless someone can provide a realistic, relatively 
common scenario under which this would pose a significant security 
problem.

Speaking of Apache, the well-known double-extension handling issue that 
enables arbitrary upload/execution of dangerous files like abc.php.gif 
also doesn't have a CVE [I don't think] for similar reasons, that it is 
well-documented behavior.

- Steve



On Tue, 12 Jul 2011, Josh Bressers wrote:

> I'm going to leave this one for MITRE.
>
> Thanks.
>
> --
>    JB
>
> ----- Original Message -----
>> -----BEGIN PGP SIGNED MESSAGE-----
>> Hash: SHA1
>>
>> Hello List,
>>
>> Is it possible to assign a CVE for documented behavior? Communication
>> with apache security showed, that following symlinks to arbitrary
>> locations is a documented feature, even when "-FollowSymLink" option
>> is
>> in place. This allows any user with, that can modify some content
>> served
>> by apache to access any content accessible by the apache process, also
>> content not visible to the user (e.g. outside the ftp-upload directory
>> or forbidden like /proc/http-pid/maps). Due to the small window of
>> opportunity, this might be relevant mostly when user can already
>> execute
>> code on the machine, so it is not a big issue. /proc/<pid>/mem is
>> protected, when apache is running with setuid, so key material cannot
>> be
>> extracted using range headers. PUT was not tested so far.
>>
>> See also
>>
>> http://www.halfdog.net/Security/2011/ApacheNoFollowSymlinkTimerace/
>>
>> - --
>> http://www.halfdog.net/
>> PGP: 156A AE98 B91F 0114 FE88 2BD8 C459 9386 feed a bee
>> -----BEGIN PGP SIGNATURE-----
>> Version: GnuPG v1.4.6 (GNU/Linux)
>>
>> iD8DBQFOHC4exFmThv7tq+4RAooyAJ9Vh7F49em+AVT1HosEquCPS+olqQCfdVCO
>> PDcCdoHHWTCHe53U+XTzefY=
>> =fVzn
>> -----END PGP SIGNATURE-----
>

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