Re: is gitosis secure?

From: Boyd Stephen Smith Jr. <bss@iguanasuicide.net>
Date: Jan 18, 2009, 14:19 UTC
Message-ID: <200901180819.11642.bss@iguanasuicide.net>
In-Reply-To: <87skngoifj.fsf@mid.deneb.enyo.de>

On Sunday 18 January 2009, Florian Weimer <fw@deneb.enyo.de> wrote about 'Re: is gitosis secure?':

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>* Boyd Stephen Smith, Jr.:
>> On Sunday 18 January 2009, Florian Weimer <fw@deneb.enyo.de> wrote
>>
>> about 'Re: is gitosis secure?':
>>>* Sam Vilain:
>>>> Restricted unix shells are a technology which has been proven secure
>>>> for decades now.
>>>Huh?  Things like scponly and rssh had their share of bugs, so I can
>>>see that there is some concern.  (And restricted shells used to be
>>
>> From my understanding, a restricted shell is a difficult thing to
>> escape from unless a user is able to run binaries that they have
>> written.  FWIW, I don't remember sftp or scponly having this particular
>> vulnerability.
>
>scponly issues due to interpretation conflicts:

Not sure all these apply, but I beleive some of them do, and I want to leave the CVE numbers in case someone wants to look them up.

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>CVE-2002-1469
>CVE-2004-1162
>CVE-2005-4533
>CVE-2007-6350
>CVE-2007-6415
>CVE-2004-1161

--- End of CVEs to investigate ---

>That's why I think it's not totally outlandish to assume that
>restricted shells are usually not very helpful for
>compartmentalization purposes.

I mostly agree with that statement. I make the assumption that, if the user can login via ssh (even under "only" a restricted shell) they can do anything a user in the same groups can do. I might be overestimating most people, but I don't think I'm underestimating anyone. I do *hope* that I get local privilege escalations patched before they are exploited, but I can't guarantee that. (I'm not sure there's really anyway to guarantee that, and I'd hate to upgrade a backup offline then replace the running instance. Especially if I had to go back to when the local privilege escalation was introduced [not just when it was "discovered"].)

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