From: dwalsh@redhat.com (Daniel J Walsh)
Date: Mon, 21 Feb 2011 14:23:28 -0500
Subject: [refpolicy] [patch 1/1] sudo: Fixes for sudo,
	handle /var/db/sudo
In-Reply-To: <4D62A3E8.80404@gmail.com>
References: <4D5EA91C.1080409@redhat.com>
	<1298092089.3101.51.camel@tesla.lan>	<4D62706E.9090801@redhat.com>
	<4D6271B6.8020105@gmail.com> <4D6299D4.5030001@redhat.com>
	<4D62A3E8.80404@gmail.com>
Message-ID: <4D62BBB0.4070208@redhat.com>
To: refpolicy@oss.tresys.com
List-Id: refpolicy.oss.tresys.com

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On 02/21/2011 12:42 PM, Dominick Grift wrote:
> On 02/21/2011 05:59 PM, Daniel J Walsh wrote:
>> On 02/21/2011 09:07 AM, Dominick Grift wrote:
>>> On 02/21/2011 03:02 PM, Daniel J Walsh wrote:
>>>> On 02/19/2011 12:08 AM, Guido Trentalancia wrote:
>>>>> Hello Miroslav !
> 
>>>>> On Fri, 18/02/2011 at 17.15 +0000, Miroslav Grepl wrote:
>>>>>> http://mgrepl.fedorapeople.org/F15/admin_sudo.patch
>>>>>>
>>>>>>      * Allow sudo to send signals to any domains the user could have 
>>>>>> transitioned to.
>>>>>>      * Handle /var/db/sudo
>>>>>>      * Allow users to run executables in /tmp or ~/
> 
>>>>> To the best of my knowledge, the first part of the last change is
>>>>> something really bad from a security point of view. 
> 
>>>>> System administrators put much effort to avoid that (such as
>>>>> mounting /tmp with noexec, nosuid options) !
> 
>>>>> A legitimate user does not need to store his/her executables in /tmp, as
>>>>> he/she has at least its own home directory available for that (and if
>>>>> he/she cannot write there, then he/she is probably over quota).
> 
>>>>> /tmp just "potentially provides storage space for malicious
>>>>> executables" (quoted from paragraph 2.2.1.3 of NSA public document
>>>>> "Guide to the Secure Configuration of Red Hat Enterprise Linux 5"
>>>>> Revision 4, but any decent web search engine would easily provide you
>>>>> with tons of pages relative to the cries of those whom have allowed that
>>>>> sort of thing to happen on their systems).
> 
>>>>> Regards,
> 
>>>>> Guido
> 
>>>>> _______________________________________________
>>>>> refpolicy mailing list
>>>>> refpolicy at oss.tresys.com
>>>>> http://oss.tresys.com/mailman/listinfo/refpolicy
> 
>>>> +	userdom_domtrans_user_tmp($1_sudo_t, $3)
> 
>>>> Says to run user_tmp_t files as staff_t, Which is the equivalent of if
>>>> the staff_t had executed the file directly.
> 
>>>> I guess if execution of homedir/tmp dir was turned off this could be
>>>> seen as a priv escalation.
> 
>>> refpolicy does not have the above functionality afaik.
> 
>>>> staff_t is not allowed to execute user_tmp_t, but it can if it goes
>>>> through sudo.
>>> _______________________________________________
>>> refpolicy mailing list
>>> refpolicy at oss.tresys.com
>>> http://oss.tresys.com/mailman/listinfo/refpolicy
> 
>> _______________________________________________
>> refpolicy mailing list
>> refpolicy at oss.tresys.com
>> http://oss.tresys.com/mailman/listinfo/refpolicy
> 
>> Are you saying staff_t is not allowed to execute user_tmp_t in reference
>> policy?
> 
> template(`userdom_login_user_template', `
> 	gen_require(`
> 		class context contains;
> 	')
> 
> 	userdom_base_user_template($1)
> 
> 	userdom_manage_home_role($1_r, $1_t)
> 
> 	userdom_manage_tmp_role($1_r, $1_t)
> 	userdom_manage_tmpfs_role($1_r, $1_t)
> 
> 	userdom_exec_user_tmp_files($1_t)
> 	userdom_exec_user_home_content_files($1_t)
> 
> 	userdom_change_password_template($1)
> 
> 	##############################
> 	#
> 	# User domain Local policy
> 	#
Then allowing sudo to execute them as the user role would make sense.
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