Suggestion on the 'Ensure All Files Are Owned...' items
Maura Dailey
maura at eclipse.ncsc.mil
Tue Jul 23 21:12:04 UTC 2013
The current check that's checked into git is broken. The
permissions_ungroupowned.xml check is searching the local file system
for things with group_id set to 0 and negating the result of the check.
That's all it's doing. The permissions_unowned.xml check was doing the
same thing, but with user_ids set to 0. I feel like it was guaranteed to
fail.
On 07/23/2013 04:31 PM, Andrew Gilmore wrote:
>
> I, along with Robert, assumed that the test was using some sort of
> find(1) invocation. It appears not to be, although this OVAL is pretty
> opaque to me.
>
> When I see the current check failing against my system, I then run a
> find command, and the only output is complaints about /proc entries. I
> then assumed that this output was why the check was failing.
>
> I can confirm that this check does fail against my system, or at least
> that testcheck returns false. The results file points at /.autofsck
> and /.readahead_collect, which doesn't make sense at all.
>
> This is one of the more frustrating false positives that I have.
>
> Andrew
>
>
>
> On Tue, Jul 23, 2013 at 1:47 PM, Maura Dailey <maura at eclipse.ncsc.mil
> <mailto:maura at eclipse.ncsc.mil>> wrote:
>
> Just an aside, I did some poking around, and it is possible to
> eliminate directories from the search. I looked at the USGCB
> stuffs and here's what I put together for
> file_permissions_unowned.xml in OVAL to eliminate /proc. I can do
> the same for the group id version. To add more exclusions, add an
> '|' after proc, and type in another directory path. It doesn't
> seem to care if you escape the forward slashes, but I left that in
> just in case the behavior changes later.
>
> If anyone does figure out how to query PAM or nslcd/nscd for
> network user ids, I think you can add it as an extra filter option
> to the file_permissions_unowned_object.
>
> Please note, I have not gotten a single failure with this check
> against /proc. I get thousands of failures on my workstation,
> since I have large git repositories checked out to directories
> owned by my network account on the root hard drive.
>
> |<def-group>||
> || <definition class="compliance" id="file_permissions_unowned"
> version="1">||
> || <metadata>||
> || <title>Find files unowned by a user</title>||
> || <affected family="unix">||
> || <platform>Red Hat Enterprise Linux 6</platform>||
> || </affected>||
> || <description>All files should be owned by a
> user</description>||
> || </metadata>||
> || <criteria>||
> || <criterion comment="Check all files and make sure they are
> owned by a user" test_ref="file_permissions_unowned_test" />||
> || </criteria>||
> || </definition>||
> ||
> || <unix:file_state
> id="file_permissions_unowned_userid_list_match" version="1">||
> || <unix:user_id var_check="at least one"
> var_ref="file_permissions_unowned_userid_list" datatype="int" />||
> || </unix:file_state>||
> ||
> || <local_variable id="file_permissions_unowned_userid_list"
> comment="List of valid user ids" datatype="int" version="1">||
> || <object_component item_field="subexpression"
> object_ref="file_permissions_unowned_userid_list_object" />||
> || </local_variable>||
> ||
> || <ind:textfilecontent54_object
> id="file_permissions_unowned_userid_list_object" version="1">||
> ||<ind:filepath>/etc/passwd</ind:filepath>||
> || <ind:pattern operation="pattern
> match">^[^:]+:[^:]+:([\d]+):[\d]+:[^:]*:[^:]+:[^:]*$</ind:pattern>||
> || <ind:instance operation="greater than or equal"
> datatype="int">1</ind:instance>||
> || </ind:textfilecontent54_object>||
> ||
> || <unix:file_object comment="all local files"
> id="file_permissions_unowned_object" version="1">||
> || <unix:behaviors recurse="symlinks and directories"
> recurse_direction="down" recurse_file_system="local" />||
> || <unix:filepath operation="pattern
> match">^(?!\/proc)/</unix:filepath>||
> || <filter
> action="exclude">file_permissions_unowned_userid_list_match</filter>||
> || </unix:file_object>||
> ||
> || <unix:file_test check="all" check_existence="none_exist"
> comment="Check user ids on all files on the system"
> id="file_permissions_unowned_test" version="1">||
> || <unix:object object_ref="file_permissions_unowned_object" />||
> || </unix:file_test>||
> ||</def-group>|
>
> - Maura Dailey
>
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