[<prev] [next>] [<thread-prev] [day] [month] [year] [list]
Date: Thu, 25 Feb 2016 10:53:29 +0000
From: John Haxby <john.haxby@...cle.com>
To: oss-security@...ts.openwall.com
Subject: Re: CVE Request: bash-completion: dequote command
injection
On 24/02/16 21:58, Kurt Seifried wrote:
> I think in this case it's pretty simply "dequoting should not result in
> code execution" much like the various deserialization flaws (they should
> deserialize the data, not execute random stuff).
My immediate assumption was that an unprivileged user could leave
something lying around that root could complete on.
Within bash-completion, most of the uses of dequote are to find a config
file so there'd be a degree of social engineering to persuade root to
use a config file of your choice. The other main use seems to be in
_parse_help() and _parse_usage() which parse gnu-style help and
bsd-style usage respectively and that might not need as much social
engineering to exploit. I didn't investigate further.
Whether or not this turns out to be exploitable at all in
bash-completion, I do agree with Kurt though.
jch
>
> On Wed, Feb 24, 2016 at 2:56 PM, Fernando Muñoz <fernando@...l-life.com>
> wrote:
>
>> Hello Eric,
>>
>> I never mentioned privilege escalation.
>>
>> This issue how ever could appear when a different application uses
>> user input and calls "dequote" function that not only dequotes, but
>> also executes it as a command. If mitre doesn't consider it CVE worth,
>> that's OK!
>>
>> Regards.
>>
>>
>>
>> On Wed, Feb 24, 2016 at 3:58 PM, Eric Blake <eblake@...hat.com> wrote:
>>> On 02/24/2016 12:08 PM, Fernando Muñoz wrote:
>>>> Marcelo Echeverria and Fernando Muñoz discovered that the dequote
>>>> function included in bash-completion allows to execute arbitrary
>>>> commands since it uses the eval function to call printf and perform
>>>> the actual dequoting. bash-completion is included on Debian, Ubuntu
>>>> OpenSuse [1] and probably other distros.
>>>
>>> But what is the privilege escalation? This is no different than
>>> incorrectly using 'eval' in a shell script - you may have buggy code,
>>> and have an easy-to-trigger bug, but if you can't escalate privileges,
>>> how it is a CVE?
>>>
>>> --
>>> Eric Blake eblake redhat com +1-919-301-3266
>>> Libvirt virtualization library http://libvirt.org
>>>
>>
>
>
>
Powered by blists - more mailing lists
Please check out the
Open Source Software Security Wiki, which is counterpart to this
mailing list.
Confused about mailing lists and their use?
Read about mailing lists on Wikipedia
and check out these
guidelines on proper formatting of your messages.
