LJK/Security Reference Manual


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RETAIN

Ensure batch and print job retention conform to policy.

Violation reports

Constraint Nature of the violation
BATCHJALL Some batch job is not set for unconditional retention
BATCHJERR Some batch job is not set for retention on error
BATCHJTIM Some batch job is not set for timed retention
BATCHQALL Some batch queue is not set for unconditional retention
BATCHQERR Some batch queue is not set for retention on error
PRINTJALL Some print job is not set for unconditional retention
PRINTJERR Some print job is not set for retention on error
PRINTJTIM Some print job is not set for timed retention
PRINTQALL Some print queue is not set for unconditional retention
PRINTQERR Some print queue is not set for retention on error
UNHANDLED Error retention of a job exceeds remediation time limit

Description

The tests for the *QALL and *QERR constraints determine whether SET QUEUE/RETAIN= settings on batch and print queues conform to policy.

The tests for the *JALL, *JERR and *JTIM constraints determine whether SUBMIT/RETAIN= or PRINT/RETAIN= settings conform to policy.

The test for the UNHANDLED constraint determines whether a job has been retained too long after an error without being handled (and deleted or released).

Default policy

Retention on error is require for all queues and retained jobs must be handled within four days

Customizing

Since SUBMIT and PRINT qualifiers can override queue defaults, these tests look at both the queue defaults and how individual jobs get submitted

Selector

Limits

Constraint Value Default
BATCHJALL FALSE or TRUE FALSE
BATCHJERR FALSE or TRUE TRUE
BATCHJTIM time interval +0-00:00:00.00
BATCHQALL FALSE or TRUE FALSE
BATCHQERR FALSE or TRUE TRUE
PRINTJALL FALSE or TRUE FALSE
PRINTJERR FALSE or TRUE TRUE
PRINTJTIM time interval +0-00:00:00.00
PRINTQALL FALSE or TRUE FALSE
PRINTQERR FALSE or TRUE TRUE
UNHANDLED 0-n minutes 5760

Exemptions

Constraint Value Parameters
BATCHJALL FALSE or TRUE <node>, <queue-name>/<username>/<job-name>
BATCHJERR FALSE or TRUE <node>, <queue-name>/<username>/<job-name>
BATCHJTIM +[dddd-][hh:mm:ss.cc]||<node>, <queue-name>/<username>/<job-name> BATCHQALL
FALSE or TRUE <node>, <queue-name> BATCHQERR
FALSE or TRUE <node>, <queue-name> PRINTJALL
FALSE or TRUE <node>, <queue-name>/<username>/<job-name> PRINTJERR
FALSE or TRUE <node>, <queue-name>/<username>/<job-name> PRINTJTIM
+[dddd-][hh:mm:ss.cc]||<node>, <queue-name>/<username>/<job-name> PRINTQALL FALSE or TRUE
<node>, <queue-name> PRINTQERR FALSE or TRUE
<node>, <queue-name> UNHANDLED 0-n
<node>, <queue-name>/<username>/<job-name>

Practical considerations

Requiring retention on batch job errors can help detect confused mishandling of data.

RESTART

Ensure that use of queue restart capability conform to policy.

Violation reports

Constraint Nature of the violation
BATPROHIB Batch job was submitted /RESTART in violation of policy
BATREQUIRE Batch job was submitted /NORESTART in violation of policy
PRIPROHIB Print job was submitted /RESTART in violation of policy
PRIREQUIRE Print job was submitted /NORESTART in violation of policy

Description

This element supports tests regarding whether the /RESTART capability is specified for jobs in print queues (where it is the VMS default) and batch queues (where it is not the VMS default).

Default policy

Print jobs must be submitted /RESTART

Customizing

Use the tests for this element to ensure batch and print operations are carried out in a reliable fashion

Selector

Limits

Constraint Value Default
BATPROHIB FALSE or TRUE FALSE
BATREQUIRE FALSE or TRUE FALSE
PRIPROHIB FALSE or TRUE FALSE
PRIREQUIRE FALSE or TRUE TRUE

Exemptions

Constraint Value Parameters
BATPROHIB FALSE or TRUE <node>, <queue-name>/<username>/<job-name>
BATREQUIRE FALSE or TRUE <node>, <queue-name>/<username>/<job-name>
PRIPROHIB FALSE or TRUE <node>, <queue-name>/<username>/<job-name>
PRIREQUIRE FALSE or TRUE <node>, <queue-name>/<username>/<job-name>

Practical considerations

This element does not consider the issue of whether batch jobs are making efficient use of the BATCH$RESTART capability, since that requires analysis of individual batch jobs.

6.7 TERM Tests

Tests in the TERM facility deal with terminal protection. Security-relevant system parameters affecting terminal security are not tested, since their effect can be undone by DCL commands from privileged usernames (typically in the site-specific system startup command procedure). The approach taken by LJK/Security is to consider the resulting security rather than how that state was achieved.

Exemptions are based on node name and terminal name.

The node name in an exemption for the TERM facility can include standard VMS wildcard characters (% and *).

The terminal name in an exemption for the TERM facility can include standard VMS wildcard characters (% and *).


ACLIDENT

Ensure that identifier types used in access control lists conform to policy.

Violation reports

Constraint Nature of the violation
NOGENERAL General identifier used in violation of policy
NOSYSTEM System-defined identifier used in violation of policy
NOUIC UIC identifier used in violation of policy

Description

Use of UIC identifiers directly in access control lists leads to problems if user responsibilities are changed, since control of the access they have been granted is distributed throughout the system.

The purpose of this test is to ensure that identifiers used in Identifier Access Control Entries are of acceptable types.

Default policy

Identifiers in ACLs must not be UIC identifiers

Customizing

The options of prohibiting General and System identifiers are provided for flexibility, but are not useful in most circumstances. The main customization which might be desired is to remove the prohibition against the use of UIC identifiers

Selector

Limits

Constraint Value Default
NOGENERAL FALSE or TRUE FALSE
NOSYSTEM FALSE or TRUE FALSE
NOUIC FALSE or TRUE TRUE

Exemptions

Constraint Value Parameters
NOGENERAL FALSE or TRUE <node>, <device-name>
NOSYSTEM FALSE or TRUE <node>, <device-name>
NOUIC FALSE or TRUE <node>, <device-name>

Practical considerations

In cases where existing use of UIC identifiers is pervasive temporary customization might be required.

AUTOLOGIN

Ensure presence of entries in the autologin file (SYSALF.DAT) complies with policy.

Violation reports

Constraint Nature of the violation
ENTRY Autologin is used in violation of policy
NONCAPTIVE Autologin is used to a non-captive username
NOPASSWORD Autologin is used without a password
NOSUCHUSER Autologin specifies a Username that does not exist or is disabled
PRIVPROHIB Autologin is used to a privileged username
ABSOLUTHI Autologin is used to a privileged username

Description

Entries in the autologin file can be used to automatically log a particular terminal in to a designated account when the carriage-return key is pressed. Such accounts can be set up either with or without passwords, but even when passwords are required, the automatic choice of username can provide an interloper "part of the puzzle".

The purpose of these tests are to ensure that any entries in the autologin file complies with organization-wide security policy.

Default policy

No use of the autologin file is permitted

Customizing

Establish exemptions based on individual terminal names to permit limited use of autologin files. Change the limits to permit unrestricted use of autologin files. selector Limits and exemptions for test TERM_AUTOLOGIN_PRIVPROHIB can take a selector consisting of a privilege name.

Thus, each can be set once for each possible privilege. When using the Command Interface if you do not specify a selector when changing the limit or exemptions your change applies to all privileges.

Limits

Constraint Value Default
ENTRY FALSE or TRUE TRUE
NONCAPTIVE FALSE or TRUE TRUE
NOPASSWORD FALSE or TRUE TRUE
NOSUCHUSER FALSE or TRUE TRUE
PRIVPROHIB FALSE or TRUE TRUE *
ABSOLUTHI Category-None---Category-All Category-Normal

* FALSE value for privilege TMPMBX.

Exemptions

Constraint Value Parameters
ENTRY FALSE or TRUE <node>,<device-name>
NONCAPTIVE FALSE or TRUE <node>,<device-name>
NOPASSWORD FALSE or TRUE <node>,<device-name>
NOSUCHUSER FALSE or TRUE <node>,<device-name>
PRIVPROHIB FALSE or TRUE <node>,<device-name>
ABSOLUTHI Category-None---Category-All <node>,<device-name>

Practical considerations

Manual methods must be used to ensure that named terminals are actually in their putative locations. Assumptions can be readily thwarted by cabling changes.

The test ABSOLUTHI is sufficient to express simpler limitations based on privilege level.

If a more complicated selection of privileges is required, it may be necessary to use the test PRIVPROHIB.


BROADCAST

Determine whether enable state for broadcast messages conforms to policy.

Violation reports

Constraint Nature of the violation
PROHIBITED Broadcast messages are enabled in violation of policy
REQUIRED Broadcast messages are disabled in violation of policy

Description

In certain situations the permanent characteristics of terminals to enable or disable reception of broadcast messages can have security implications.

These tests are intended to allow reporting when permanent terminal characteristics do not conform to policy.

Default policy

Enabling of broadcast messages is neither prohibited nor required

Customizing

You can set limits to indicate a general policy, and exemptions on an individual basis. The most likely situation would be to have the limits require broadcast messages be enabled and set exemptions for other cases

Selector

Limits

Constraint Value Default
PROHIBITED FALSE or TRUE FALSE
REQUIRED FALSE or TRUE FALSE

Exemptions

Constraint Value Parameters
PROHIBITED FALSE or TRUE <node>, <device-name>
REQUIRED FALSE or TRUE <node>, <device-name>

Practical considerations

The permanent terminal broadcast setting is only one factor in the delivery of broadcast messages. It can be overridden by the user logged in at a terminal (without privilege). The types of messages delivered can be subsetted by that user through the SET BROADCAST command.

DIALUP

Determine whether designation as dialup conforms to policy.

Violation reports

Constraint Nature of the violation
PROHIBITED Designated as dialup in violation of policy
REQUIRED Designated as non-dialup in violation of policy

Description

VMS provides the capability to designate certain terminal lines as "dialup" and restrict system access to particular usernames or particular files based on whether the access is coming over a "dialup" line.

Trusting the "dialup" designation in the permanent characteristics of a terminal can be illusory, since a non-dialup line can have a modem attached to it.

On the other hand, some sites use the "dialup" designation for other meanings which are either not relevant to security or do not have the same risk of spoofing.

Default policy

Designation as dialup is prohibited

Customizing

Customization is in order if your organization has some other use for the "dialup" designation. It also may be required in cases where a higher governing authority mandates such a distinction

Selector

Limits

Constraint Value Default
PROHIBITED FALSE or TRUE TRUE
REQUIRED FALSE or TRUE FALSE

Exemptions

Constraint Value Parameters
PROHIBITED FALSE or TRUE <node>, <device-name>
REQUIRED FALSE or TRUE <node>, <device-name>

Practical considerations

Keeping track of which lines are dialup also means tracking all changes in wiring schemes for various nodes.

DISCONNECT

Determine whether enabling of virtual terminals conforms to policy.

Violation reports

Constraint Nature of the violation
PROHIBITED Disconnect allowed is enabled in violation of policy
REQUIRED Disconnect allowed is disabled in violation of policy

Description

Provision of virtual terminals allows a user whose session is interrupted by circuit disconnection to continue the existing session by supplying the appropriate password after connecting again. This was originally developed as a continuity-of-service feature. Since then as concern about security has grown, the manual DISCONNECT command has become more important as a method for achieving what various security disciplines call "Session Lock".

Some sites may have specific requirements mandating that virtual terminals not be enabled.

Default policy

Enabling of disconnection is neither prohibited nor required

Customizing

Customize here if you have the need to ensure uniformity across all nodes owned by your organization

Selector

Limits

Constraint Value Default
PROHIBITED FALSE or TRUE FALSE
REQUIRED FALSE or TRUE FALSE

Exemptions

Constraint Value Parameters
PROHIBITED FALSE or TRUE <node>, <device-name>
REQUIRED FALSE or TRUE <node>, <device-name>

Practical considerations

The length of time a disconnected process will remain available can be controlled on a node-by-node basis.

HANGUP

Determine whether forcing hangup on logout conforms to policy.

Violation reports

Constraint Nature of the violation
PROHIBITED Hangup on logout is enabled in violation of policy
REQUIRED Hangup on logout is disabled in violation of policy

Description

Forcing hangup on logout is generally viewed as an availability-of-service feature, since it frees dialup lines for use by another caller. Most sites combine it with allowing users to use the /NOHANGUP qualifier on a particular logout, since the goal is to defend against unknowing failure to properly terminate a call.

Default policy

Hangup on logout is required

Customizing

In most cases, provision of the MODHANGUP capability is sufficient to meet user needs and no customization of this test is required

Selector

Limits

Constraint Value Default
PROHIBITED FALSE or TRUE FALSE
REQUIRED FALSE or TRUE TRUE

Exemptions

Constraint Value Parameters
PROHIBITED FALSE or TRUE <node>, <device-name>
REQUIRED FALSE or TRUE <node>, <device-name>

Practical considerations

Use of an application which performs process deletion rather than allowing the user to invoke LOGOUT may require that hangup on logout not be enabled.

MODEM

Determine whether specification of modem control conforms to policy.

Violation reports

Constraint Nature of the violation
PROHIBITED Modem control is enabled in violation of policy
REQUIRED Modem control is disabled in violation of policy

Description

Enabling modem control specifies that VMS will provide and expect proper modem signalling on a particular terminal line. It does not necessarily have anything to do with dialup modems, as many other types of data communications equipment require and provide modem control signals.

Default policy

Enabling of modem control is neither prohibited nor required

Customizing

In most cases, enforcement of particular modem control settings is not required since equipment will not work if the setting is wrong

Selector

Limits

Constraint Value Default
PROHIBITED FALSE or TRUE FALSE
REQUIRED FALSE or TRUE FALSE

Exemptions

Constraint Value Parameters
PROHIBITED FALSE or TRUE <node>, <device-name>
REQUIRED FALSE or TRUE <node>, <device-name>

Practical considerations

Cases where modem control is not provided when it might seem to be needed may indicate situations where modem cabling has been modified so as not to require such signals. This generally results in reduced information flow regarding the state of calls, and reduced security.

MODHANGUP

Determine whether allowing user modification of hangup on logout conforms to policy.

Violation reports

Constraint Nature of the violation
PROHIBITED User modification of hangup on logout is enabled in violation of policy
REQUIRED User modification of hangup on logout is disabled in violation of policy

Description

Enabling user modification of hangup on logout allows knowledgeable users to avoid having to redial calls when logging in to another session. Most sites enable it, using the hangup on logout feature of VMS only to protect against authorized but forgetful users from tying up lines after they are finished.

Default policy

Allowing user modification of hangup on logout is neither prohibited nor required

Customizing

Abuse of the LOGOUT/NOHANGUP feature may require MODHANGUP be prohibited

Selector

Limits

Constraint Value Default
PROHIBITED FALSE or TRUE FALSE
REQUIRED FALSE or TRUE FALSE

Exemptions

Constraint Value Parameters
PROHIBITED FALSE or TRUE <node>, <device-name>
REQUIRED FALSE or TRUE <node>, <device-name>

Practical considerations

Although the LOGOUT/NOHANGUP feature is supposed to be used only in cases where it is needed, some users might define DCL symbols to change every LOGOUT command into a LOGOUT/NOHANGUP command, thereby violating the spirit of the feature.

NETDEVICE

Determine whether designation as network device conforms to policy.

Violation reports

Constraint Nature of the violation
PROHIBITED Set as network device in violation of policy
REQUIRED Set as interactive device in violation of policy

Description

When terminal lines are used for asynchronous DECnet, they are automatically designated as network devices. These tests can be used to check for unauthorized asynchronous DECnet connections, if a site has sufficient staff to track all changes in network connections.

Default policy

Designation as a network device is neither prohibited nor required

Customizing

An aggressive program of tracking network connections would require setting both limits TRUE and then setting an exemption for every line (or group of lines via wildcard exemptions)

Selector

Limits

Constraint Value Default
PROHIBITED FALSE or TRUE FALSE
REQUIRED FALSE or TRUE FALSE

Exemptions

Constraint Value Parameters
PROHIBITED FALSE or TRUE <node>, <device-name>
REQUIRED FALSE or TRUE <node>, <device-name>

Practical considerations

Dynamic (dialup) asynchronous DECnet allows certain lines to change their state between network and terminal devices.

OPERATOR

Determine whether enabling for operator messages conforms to policy.

Violation reports

Constraint Nature of the violation
PROHIBITED Enabled for operator messages in violation of policy
REQUIRED Disabled from operator messages in violation of policy

Description

Certain terminals at a site are generally designated as operator terminals to receive user and program requests for operator assistance. These tests can be used to ensure that no unauthorized terminals are so enabled and to ensure that required terminals are enabled.

Default policy

Enabling as an operator terminal is prohibited

Customizing

Establish PROHIBITED exemptions for authorized operator terminals. If you want to ensure that certain terminals are enabled, set the REQUIRED limit TRUE and establish exemptions for all the "other" terminals (a tall order)

Selector

Limits

Constraint Value Default
PROHIBITED FALSE or TRUE TRUE
REQUIRED FALSE or TRUE FALSE

Exemptions

Constraint Value Parameters
PROHIBITED FALSE or TRUE <node>, <device-name>
REQUIRED FALSE or TRUE <node>, <device-name>

Practical considerations

Enabling a terminal for operator messages does not grant any ability to control anything, merely to receive information. In that light, you may not care what terminals are enabled and may prefer to relax the default PROHIBITED limit to FALSE.


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