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Date: Wed, 31 Jul 2013 02:11:46 -0600
From: Kurt Seifried <kseifried@...hat.com>
To: oss-security@...ts.openwall.com
CC: Donald Stufft <donald@...fft.io>
Subject: Re: CVE Request: Insecure Software Download in pip

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Hash: SHA1

On 07/30/2013 12:44 PM, Donald Stufft wrote:
> 
> On Jul 30, 2013, at 2:32 AM, Kurt Seifried <kseifried@...hat.com 
> <mailto:kseifried@...hat.com>> wrote:
> 
>> Signed PGP part On 07/30/2013 12:28 AM, Donald Stufft wrote:
>>> 
>>> On Jul 30, 2013, at 2:21 AM, Kurt Seifried
>>> <kseifried@...hat.com
>> <mailto:kseifried@...hat.com>
>>> <mailto:kseifried@...hat.com>> wrote:
>>> 
>>>> Signed PGP part On 07/27/2013 01:10 AM, Donald Stufft wrote:
>>>>> 
>>>>> On Jul 27, 2013, at 3:08 AM, Kurt Seifried 
>>>>> <kseifried@...hat.com <mailto:kseifried@...hat.com>
>>>> <mailto:kseifried@...hat.com>>
>>>>> wrote:
>>>>> 
>>>>>> On 07/25/2013 03:09 AM, Donald Stufft wrote:
>>>>>>> I'd like to request a CVE for pip 
>>>>>>> (https://pypi.python.org/pypi/pip/).
>>>>>>> 
>>>>>>> The mirroring support (-M, --use-mirrors) was
>>>>>>> implemented without any sort of authenticity checks and
>>>>>>> is downloaded over plaintext HTTP. Further more by
>>>>>>> default it will dynamically discover the list of
>>>>>>> available mirrors by querying a DNS entry and
>>>>>>> extrapolating from that data. It does not attempt to
>>>>>>> use any sort of method of securing this querying of the
>>>>>>> DNS like DNSSEC. Software packages are downloaded over
>>>>>>> these insecure links, unpacked, and then typically the
>>>>>>> setup.py python file inside of them is executed.
>>>>>>> 
>>>>>>> The vulnerable code is located at: - 
>>>>>>> https://github.com/pypa/pip/blob/develop/pip/index.py#L60-L64
>>
>>>>>>> 
>> 
>>>>>>> 
>>>>> -
>>>>>>> https://github.com/pypa/pip/blob/develop/pip/index.py#L205-L207
>>
>>>>>>> 
>> 
>>>>>>> 
>>>>> -
>>>>>>> https://github.com/pypa/pip/blob/develop/pip/index.py#L553-L572
>>
>>>>>>> 
>> 
>>>>>>> 
>>>>> -
>>>>>>> https://github.com/pypa/pip/blob/develop/pip/index.py#L999-L1024
>>
>>>>>>> 
>> 
>>>>>>> 
>>>>> 
>>>>>>> 
>>>>>>> 
>>>> The affected versions are every released version since 0.8.1 
>>>> which
>>>>>>> are: 0.8.1, 0.8.2, 0.8.3, 1.0, 1.0.1, 1.0.2, 1.1, 1.2, 
>>>>>>> 1.2.1, 1.3, 1.3.1, 1.4
>>>>>>> 
>>>>>>> I'm not aware of this issue having ever had a CVE
>>>>>>> requested for it and my attempts to search the CVE
>>>>>>> database did not appear to turn up anything relevant
>>>>>>> but the search doesn't appear to be the greatest so I
>>>>>>> may have missed it.
>>>>>>> 
>>>>>>> I'm hoping to land a patch for this in a future
>>>>>>> release (current iteration of patch available at 
>>>>>>> https://github.com/dstufft/pip/compare/remove-mirror-support)
>>
>>>>>>> 
>> 
>>>>>>> 
>>>>> but there is no planned fix version as of yet.
>>>>>>> 
>>>>>>> ----------------- Donald Stufft PGP: 0x6E3CBCE93372DCFA
>>>>>>> // 7C6B 7C5D 5E2B 6356 A926 F04F 6E3C BCE9 3372 DCFA
>>>>>> 
>>>>>> Was it supposed to be secure (like was this explicitly 
>>>>>> supposed to be all encrypted/etc.)? This sounds more
>>>>>> like security hardening than a security vulnerability.
>>>>>> 
>>>>>> - -- Kurt Seifried Red Hat Security Response Team (SRT)
>>>>>> PGP: 0x5E267993 A90B F995 7350 148F 66BF 7554 160D 4553
>>>>>> 5E26 7993
>>>>>> 
>>>>> 
>>>>> The mirroring protocol explicitly included provisions for 
>>>>> verification which was not being done.
>>>>> 
>>>>> http://www.python.org/dev/peps/pep-0381/#mirror-authenticity
>>
>>>>> 
>>> 
>>>>> ----------------- Donald Stufft PGP: 0x6E3CBCE93372DCFA // 
>>>>> 7C6B 7C5D 5E2B 6356 A926 F04F 6E3C BCE9 3372 DCFA
>>>>> 
>>>> 
>>>> So to confirm, we're talking about the line:
>>>> 
>>>> "Verification is not needed when downloading from central
>>>> index, and should be avoided to reduce the computation
>>>> overhead."
>>>> 
>>>> So accessing the central index is done over HTTP by default,
>>>> no support for HTTPS previous to commit
>>>> 
>> https://github.com/pypa/pip/commit/e80c387a26858c4d7ff43c5f030b04b03fd43dfe
>>
>> 
>> 
>>>> 
>> correct?
>>>> 
>>>> - -- Kurt Seifried Red Hat Security Response Team (SRT) PGP: 
>>>> 0x5E267993 A90B F995 7350 148F 66BF 7554 160D 4553 5E26 7993
>>>> 
>>>> 
>>> 
>>> The central index is pypi.python.org <http://pypi.python.org>
>> <http://pypi.python.org> and
>>> historically (and at the time of that commit) it was not
>>> accessed securely (plaintext HTTP, no authenticity checks etc).
>>> The mirroring support, (located at, a.pyp.python.org
>> <http://a.pyp.python.org>
>>> <http://a.pyp.python.org>, b.pypi.python.org
>>> <http://b.pypi.python.org> <http://b.pypi.python.org>, …) which
>>> that commit adds and PEP381 deals with, was supposed to have
>>> authenticity checking preventing a malicious mirror operator
>>> from attacking you by checking a html manifest that included
>>> hashes was signed by a key owned by the central index
>>> (pypi.python.org <http://pypi.python.org>
>> <http://pypi.python.org>). That
>>> commit does not include checking that the mirrors are not
>>> hosting content that differs from the central index.
>>> 
>>> So basically the lack of authenticity checking when installing 
>>> directly from the central index is a separate issue which has
>>> been (mostly) addressed with pip 1.3, and more so with 1.4.
>>> However this request deals explicitly with the implementation
>>> of the protocol for installing from the hosts that mirror the
>>> central index, but are not the central index.
>>> 
>>> For what it's worth my PR to fix it is here 
>>> https://github.com/pypa/pip/pull/1098
>>> 
>>> Between myself, the comment on the PR, and the mailing list I
>>> have 3 pip developers +1ing the change so it's likely it's
>>> going to land unless one of the others has concerns.
>>> 
>>> ----------------- Donald Stufft PGP: 0x6E3CBCE93372DCFA //
>>> 7C6B 7C5D 5E2B 6356 A926 F04F 6E3C BCE9 3372 DCFA
>>> 
>> 
>> So does this need two CVEs potentially? E.g. one for the central
>> issue and one for the mirror issue? In any event if it's the same
>> issue but they get fixed in different versions that would trigger
>> a CVE split.
>> 
> 
> There was a CVE for pip not verifying TLS,
> https://access.redhat.com/security/cve/CVE-2013-1629 However that
> says it was RESERVED so I'm not sure how to make that unreserved?
> I've not done much with requesting CVEs before.

Ok I have no info on that CVE, is it embargoed? I can't find it in
google after a quick search. I need to see that one before I can
assign anything. As for the reserved thing:

http://en.wikipedia.org/wiki/Common_Vulnerabilities_and_Exposures#Description


> I do believe they are separate issues though and deserve separate 
> CVEs.
> 
> Also as a status update my fix for this just landed in the develop
> branch this morning so the fix will be released in 1.5. It removes
> --use-mirrors and the automatic discovery via DNS, and it makes the
> --mirrors option (which allowed you to specify which mirror you
> wanted) an alias for --extra-index-url. It's true that the mirrors
> are all still only available on HTTP but I don't believe that piece
> is a problem for pip as the user would have had to explicit use
> ``--mirrors http://f.pypi.python.org/simple``.
> 
> So It's fixed :) Question is just now does it get a CVE so I can
> try to document our change log with CVE numbers for these issues.



- -- 
Kurt Seifried Red Hat Security Response Team (SRT)
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