LJK/Security Reference Manual


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MVTIMEOUT

Determine how long VMS will wait for mount verification in case of a device error.

Violation reports

Constraint Nature of the violation
ABSOLUTLO Timeout period is shorter than policy allows.
ABSOLUTHI Timeout period is longer than policy allows.

Description

System parameter MVTIMEOUT controls how long VMS will stall a process while waiting for a device error to be cleared. After that time period, an error is returned to the user.

Default policy

The default limits are set to widely bracket the VMS default value of 3600 for system parameter MVTIMEOUT

Customizing

If local policy is to change the VMS defaults, it should be reflected in limits or exemptions

A limit or exemption with a value of zero means there is no value which is considered unacceptable

Selector

Limits

Constraint Value Default
ABSOLUTLO 0---64,000 (seconds) 300
ABSOLUTHI 0---64,000 (seconds) 64,000

Exemptions

Constraint Value Parameters
ABSOLUTLO 0---64,000 (seconds) <node>
ABSOLUTHI 0---64,000 (seconds) <node>

Practical considerations

Excessively long timeout periods delay detection of errors and leave user processes hung with no indication of the problem. Excessively short timeout periods reduce the chance that a device error can be corrected without aborting user transactions.

OPCOM

Determine whether OPCOM state conforms to policy.

Violation reports

Constraint Nature of the violation
PROHIBITED OPCOM is started in violation of policy
REQUIRED OPCOM is stopped in violation of policy

Description

Security alarm transmission to operators uses the OPCOM process, and if that process is not running there will be no notification. In addition, for versions of VMS prior to V5.2, the OPCOM process is required in order to record security alarms on disk.

Default policy

The OPCOM process must be running

Customizing

Add an exemption to the REQUIRED test for any node which you wish to exempt from requirements to run the OPCOM process

Selector

Limits

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

Exemptions

Constraint Value Parameters
PROHIBITED FALSE or TRUE <node>
REQUIRED FALSE or TRUE <node>

Practical considerations

Future versions of VMS (after V5.4) may provide an alternative method of operator notification without requiring the OPCOM process.

POLICY

See if LJK/Security policy modification history conforms to policy.

Violation reports

Constraint Nature of the violation
AUDEVTDAYS The last LJK/Security policy modification of auditable events was longer ago than the maximum allowed
MODIFYDAYS The last LJK/Security policy modification was longer ago than the maximum allowed

Description

The tests within this element determines whether the LJK/Security policy used in this assessment has been changed recently enough.

Default policy

No particular policy modification schedule is required

Customizing

Some external requirements require ongoing modification of policy values

Selector

Limits

Constraint Value Default
AUDEVTDAYS number of days 0
MODIFYDAYS number of days 0

Exemptions

Constraint Value Parameters
AUDEVTDAYS number of days <node>
MODIFYDAYS number of days <node>

Practical considerations

While LJK/Security can detect policy modification dates, it cannot determine whether they were based on sound judgement.

PWDHISTORY

Determine whether password history parameters conform to policy.

Violation reports

Constraint Nature of the violation
MINLIFE Password history lifetime is shorter than policy allows.
MAXLIFE Password history lifetime is longer than policy allows.
MINLIMIT Password history entry limit is less than policy allows.
MAXLIMIT Password history entry limit is more than policy allows.

Description

Logical names SYS$PASSWORD_HISTORY_LIFETIME and SYS$PASSWORD_HISTORY_LIMIT can be used to alter the VMS defaults of 365 days and 60 entries respectively.

Regardless of whether those logical names are used or not, tests for this element will determine if the values in effect on the system conform to policy.

Default policy

The VMS default values of 365 days and 60 entries is required

Customizing

Add exemptions or modify limits in your policy if you want to permit deviations from the VMS default.

A limit or exemption with a value of zero means there is no value which is considered unacceptable

Selector

Limits

Constraint Value Default
MINLIFE 0---3650 365
MAXLIFE 0---3650 365
MINLIMIT 2---255 60
MAXLIMIT 2---255 60

Exemptions

Constraint Value Parameters
MINLIFE 0---3650 <node>
MAXLIFE 0---3650 <node>
MINLIMIT 2---255 <node>
MAXLIMIT 2---255 <node>

Practical considerations

In most cases, the VMS defaults are adequate and this test merely ensure there are no local deviations.

PWDPOLICY

Determine whether site-specific password policy on disk conforms to policy.

Violation reports

Constraint Nature of the violation
LOADPWDPRO Loading site code is enabled in violation of policy.
LOADPWDREQ Loading site code is disabled in violation of policy.
PWDEXEPRO Site-specific password policy is provided in violation of policy.
PWDEXEREQ Site-specific password policy is absent in violation of policy.
HASHPWDPRO Site-specific password algorithm is provided in violation of policy.
HASHPWDREQ Site-specific password algorithm is absent in violation of policy.

Description

Tests VMS_LOADPWDPRO and VMS_LOADPWDREQ test whether system parameter LOAD_PWD_POLICY is set.

Tests VMS_PWDEXEPRO and VMS_PWDEXEREQ test whether the image SYS$LIBRARY:VMS$PASSWORD_POLICY.EXE is provided.

Tests VMS_HASHPWDPRO and VMS_HASHPWDREQ test whether the image SYS$LOADABLE_IMAGES:SYS$HASH_PASSWORD.EXE is provided. This capability is provided only on VMS V5.4 or greater.

System parameter LOAD_PWD_POLICY is only available on VMS V5.4 or greater.

Default policy

Password policy options are prohibited, since they could be used as the basis for further efforts by a successful attacker

Customizing

Limits and exemptions for tests VMS_LOADPWD* and VMS_PWDEXE* should be set in concert, since the parameter setting and image presence must be coordinated to have the desired effect

Selector

Limits

Constraint Value Default
LOADPWDPRO FALSE or TRUE TRUE
LOADPWDREQ FALSE, TRUE or TRY FALSE
PWDEXEPRO FALSE or TRUE TRUE
PWDEXEREQ FALSE, TRUE or TRY FALSE
HASHPWDPRO FALSE or TRUE TRUE
HASHPWDREQ FALSE, TRUE or TRY FALSE

Exemptions

Constraint Value Parameters
LOADPWDPRO FALSE or TRUE <node>
LOADPWDREQ FALSE, TRUE or TRY <node>
PWDEXEPRO FALSE or TRUE <node>
PWDEXEREQ FALSE, TRUE or TRY <node>
HASHPWDPRO FALSE or TRUE <node>
HASHPWDREQ FALSE, TRUE or TRY <node>

Practical considerations

The tests in the element do nothing to test whether the site-specific code provided is the correct code.

It is important that no unauthorized site specific password policy be in use, since it might have been left as a back door into the system by an attacker who successfully gained privileged access. Attackers in the past have gone so far as to patch the LOGINOUT image, and this mechanism, though useful for its stated purpose, could be hazardous if an attacker gains control. Among other tactics used in the past, collecting the cleartext passwords of individual users has sometimes given attackers some help in guessing what passwords were chosen by the same users on systems in the same network which have not yet been compromised.


REBLDSYS

Determine whether the system disk will be rebuilt after a system crash.

Violation reports

Constraint Nature of the violation
PROHIBITED System parameter ACP_REBLDSYSD is 1 in violation of policy
REQUIRED System parameter ACP_REBLDSYSD is 0 in violation of policy

Description

Free space bit maps on various disks may be incorrect after a system crash. For most disks, this is corrected by the (default) MOUNT/REBUILD qualifier. For the system disk, however, rebuilding is controlled by the system parameter ACP_REBLDSYSD.

Default policy

Rebuilding is required

Customizing

To ensure that system disks are rebuilt, you should set REQUIRED to TRUE. Setting PROHIBITED to TRUE will allow faster reboots. Setting both limits to FALSE will allow local discretion

Selector

Limits

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

Exemptions

Constraint Value Parameters
PROHIBITED FALSE or TRUE <node>
REQUIRED FALSE or TRUE <node>

Practical considerations

Rebuilding the system disk can be time-consuming, denying service to some extent, depending on local standards.

Generally, the worst outcome of failing to rebuild the system disk (or any other disk, in fact) is just the unavailability of some free space on the disk. This is due to the "careful write" methods of the VMS file system. If denial of service time is more onerous than denial of disk space at your site, you might prefer to set PROHIBITED to TRUE and REQUIRED to FALSE.


REMEDIATE

Specify times required for generation of remediation reports.

Violation reports

Constraint Nature of the violation
CHANGES The number of days required to implement an application change
CONFIGURE The number of days required to implement a parameter change
INITIALIZE The number of days required to propagate assessment results
MAXIMUM The number of days required for all applications to be exercised at least once
MEDIAN The number of days required for half of the applications to be exercised at least once
VERIFY The number of days required to verify a violation has been corrected
Y01DAYS Spare Constraint
Y02DAYS Spare Constraint
Y03DAYS Spare Constraint
Y04DAYS Spare Constraint
Y05DAYS Spare Constraint
Y06DAYS Spare Constraint

Description

The constraints within this element are not really tests, but provide organization latency used to generate remediation plans.

The constraints labeled "Spare Constraint" are for site specific definition and can be used within non-automated assessment definitions.

The other constraints are used by LJK Software in both the automated assessment definitions built into LJK/Security and also the non-automated assessment definitions included in template policy command procedures.

Default policy

Most applications run every month.

All applications run every year.

It takes 7 days to propagate violation reports.

It takes 90 days to change an application

Customizing

Change these constraints freely to match reality within your organization

Selector

Limits

Constraint Value Default
CHANGES number of days 90
CONFIGURE number of days 7
INITIALIZE number of days 7
MAXIMUM number of days 366
MEDIAN number of days 31
VERIFY number of days 7
Y01DAYS number of days 0
Y02DAYS number of days 0
Y03DAYS number of days 0
Y04DAYS number of days 0
Y05DAYS number of days 0
Y06DAYS number of days 0

Exemptions

Constraint Value Parameters
CHANGES number of days <node>
CONFIGURE number of days <node>
INITIALIZE number of days <node>
MAXIMUM number of days <node>
MEDIAN number of days <node>
VERIFY number of days <node>
Y01DAYS number of days <node>
Y02DAYS number of days <node>
Y03DAYS number of days <node>
Y04DAYS number of days <node>
Y05DAYS number of days <node>
Y06DAYS number of days <node>

Practical considerations

These tests do not really test any controls, they are used only to generate remediation schedules.


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