Re: CVE request: double-free vulnerability in logsurfer

[Timo Warns <warns () pre-sense de>]

Am 17.10.2011 12:07, schrieb Marcus Meissner:
> On Mon, Oct 17, 2011 at 12:02:29PM +0200, Timo Warns wrote:
> > Gregor Kopf of Recurity Labs GmbH found a double-free vulnerability in
> > Logsurfer affecting the function prepare_exec(). The vulnerability is caused by
> > an insufficient treatment of an error condition that is returned by the
> > function get_word() when it is unable to correctly parse its input.
> >
> > The following versions of logsurfer are affected:
> >
> >  Logsurfer 1.5b and previous versions
> >  Logsurfer+ 1.7 and previous versions
> >
> > A patch is available at 
> > http://logsurfer.git.sourceforge.net/git/gitweb.cgi?p=logsurfer/logsurfer;a=commit;h=07983748da9ea3d4954b80f02fed692fe21b1134
>
> How can this be exploited?
>
> It seems to happen in the argument handling and I doubt an attacker can inject arguments?

Logsurfer allows to use substrings of log-file entries as arguments for
calling external commands. An attacker is able to exploit this
vulnerability by injecting specially crafted strings into a log-file
that is processed by logsurfer.

Cheers, Timo