MSEC: System Security and Audit
msecgui
Presentation
msecguiYou can start this tool from the command
line, by typing msecgui as root.
is a graphic user interface for msec that allows to configure
your system security according to two approaches:
It sets the system behaviour, msec imposes modifications to the
system to make it more secure.
It carries on periodic checks automatically on the system in
order to warn you if something seems dangerous.
msec uses the concept of "security levels" which are intended to
configure a set of system permissions, which can be audited for changes or
enforcement. Several of them are proposed by Mageia, but you can define
your own customised security levels.
Overview tab
See the screenshot above
The first tab takes up the list of the different security tools with
a button on the right side to configure them:
Firewall, also found in the MCC / Security / Set up your
personal firewall
Updates, also found in MCC / Software Management / Update your
system
msec itself with some information:
enabled or not
the configured Base security level
the date of the last Periodic checks and a button to see a
detailed report and another button to execute the checks just
now.
Security settings tab
A click on the second tab or on the Security
Configure button leads to the same screen shown
below.
Basic security tab
Security levels:
After having checked the box Enable MSEC
tool, this tab allows you by a double click to choose the
security level that appears then in bold. If the box is not checked, the
level « none » is applied. The following levels are available:
Level none. This level is
intended if you do not want to use msec to control system security,
and prefer tuning it on your own. It disables all security checks
and puts no restrictions or constraints on system configuration and
settings. Please use this level only if you are knowing what you are
doing, as it would leave your system vulnerable to attack.
Level standard. This is the
default configuration when installed and is intended for casual users.
It constrains several system settings and executes daily security
checks which detect changes in system files, system accounts, and
vulnerable directory permissions. (This level is similar to levels 2
and 3 from past msec versions).
Level secure. This level is
intended when you want to ensure your system is secure, yet usable.
It further restricts system permissions and executes more periodic
checks. Moreover, access to the system is more restricted. (This
level is similar to levels 4 (High) and 5 (Paranoid) from old msec
versions).
Besides those levels, different task-oriented security are
also provided, such as the fileserver
, webserver and
netbook levels. Such levels
attempt to pre-configure system security according to the most common
use cases.
The last two levels called audit_daily
and audit_weekly are
not really security levels but rather tools for periodic checks
only.
These levels are saved in
etc/security/msec/level.<levelname>. You can
define your own customised security levels, saving them into specific
files called level.<levelname>, placed into
the folder etc/security/msec/. This function is
intended for power users which require a customised or more secure
system configuration.
Keep in mind that user-modified parameters take precedence over
default level settings.
Security alerts:
If you check the box Send security alerts by email
to:, the security alerts generated by msec are going to be
sent by local e-mail to the security administrator named in the nearby
field. You can fill either a local user or a complete e-mail address
(the local e-mail and the e-mail manager must be set accordingly). At
last, you can receive the security alerts directly on your desktop.
Check the relevant box to enable it.
It is strongly advisable to enable the security alerts option
in order to immediately inform the security administrator of possible
security problems. If not, the administrator will have to regularly
check the logs files available in
/var/log/security.
Security options:
Creating a customised level is not the only way to customise the
computer security, it is also possible to use the tabs presented here
after to change any option you want. Current configuration for msec is
stored in /etc/security/msec/security.conf. This
file contains the current security level name and the list of all the
modifications done to the options.
System security tab
This tab displays all the security options on the left side
column, a description in the centre column, and their current values on
the right side column.
To modify an option, double click on it and a new window appears
(see screenshot below). It displays the option name, a short
description, the actual and default values, and a drop down list where
the new value can be selected. Click on the OK
button to validate the choice.
Do not forget when leaving msecgui to save definitively your
configuration using the menu File -> Save the
configuration. If you have changed the settings, msecgui
allows you to preview the changes before saving them.
Network security
This tab displays all the network options and works like the
previous tab
Periodic checks tab
Periodic checks aim to inform the security administrator by means
of security alerts of all situations msec thinks potentially
dangerous.
This tab displays all the periodic checks done by msec and their
frequency if the box Enable periodic security
checks is checked. Changes are done like in the previous
tabs.
Exceptions tab
Sometimes alert messages are due to well known and wanted
situations. In these cases they are useless and wasted time for the
administrator. This tab allows you to create as many exceptions as you
want to avoid unwanted alert messages. It is obviously empty at the
first msec start. The screenshot below shows four exceptions.
To create an exception, click on the Add a
rule button
Select the wanted periodic check in the drop down list called
Check and then, enter the
Exception in the text area. Adding an exception is
obviously not definitive, you can either delete it using the
Delete button of the
Exceptions tab or modify it with a double
clicK.
Permissions
This tab is intended for file and directory permissions checking and
enforcement.
Like for the security, msec owns different permissions levels
(standard, secure, ..), they are enabled accordingly with the chosen
security level. You can create your own customised permissions levels,
saving them into specific files called perm.<levelname>
placed into the folder etc/security/msec/
. This function is intended for power users which require a customised
configuration. It is also possible to use the tab presented here after to
change any permission you want. Current configuration is stored in
/etc/security/msec/perms.conf. This file contains the
list of all the modifications done to the permissions.
Default permissions are visible as a list of rules
(a rule per line). You can see on the left side, the file or folder
concerned by the rule, then the owner, then the group and then the
permissions given by the rule. If, for a given rule:
the box Enforce is not checked, msec only
checks if the defined permissions for this rule are respected and
sends an alert message if not, but does not change anything.
the box Enforce is checked, then msec
will rule the permissions respect at the first periodic check and
overwrite the permissions.
For this to work, the option CHECK_PERMS in
the Periodic check tab must be configured
accordingly.To create a new rule, click on the
Add a rule button and fill the fields as shown in
the example below. The joker * is allowed in the File
field. “current” means no modification.
Click on the OK button to
validate the choice and do not forget when leaving to save definitively
your configuration using the menu File -> Save the
configuration. If you have changed the settings, msecgui allows
you to preview the changes before saving them.
It is also possible to create or modify the rules by editing
the configuration file /etc/security/msec/perms.conf.
Changes in the Permission
tab (or directly in the configuration file) are taken into
account at the first periodic check (see the option CHECK_PERMS in the
Periodic checks tab). If you want them to
be taken immediately into account, use the msecperms command in a console
with root rights. You can use before, the msecperms -p command to know the
permissions that will be changed by msecperms.
Do not forget that if you modify the permissions in a
console or in a file manager, for a file where the box Enforce
is checked in the Permissions tab
, msecgui will write the old permissions back after a while,
accordingly to the configuration of the options CHECK_PERMS and
CHECK_PERMS_ENFORCE in the Periodic Checks tab
.