LJK/Security Reference Manual


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CONNECT

Determine whether enabling of alarms or audits for connection events through DECnet Phase IV, DECwindows, $IPC and SYSMAN conforms to policy.

Violation reports

Constraint Nature of the violation
ALPROHIBIT Connection security alarms are enabled in violation of policy
ALREQUIRE Connection security alarms are disabled in violation of policy
AUPROHIBIT Connection security audits are enabled in violation of policy
AUREQUIRE Connection security audits are disabled in violation of policy

Description

Use of the qualifier /ENABLE=CONNECTION with the SET AUDIT/ALARM or SET AUDIT/AUDIT command causes the corresponding reporting when a connection takes place.

Default policy

Enabling of Connection security alarms and audits is neither prohibited nor required

Customizing

Set limits TRUE to establish a general prohibition of or requirement for the enabling of Connection security alarms or audits. Then establish exemptions for any individual nodes which are not to be subjected to the general rule. selector

Limits

Constraint Value Default
ALPROHIBIT FALSE or TRUE FALSE
ALREQUIRE FALSE, TRUE or TRY FALSE
AUPROHIBIT FALSE or TRUE FALSE
AUREQUIRE FALSE, TRUE or TRY FALSE

Exemptions

Constraint Value Parameters
ALPROHIBIT FALSE or TRUE <node>
ALREQUIRE FALSE, TRUE or TRY <node>
AUPROHIBIT FALSE or TRUE <node>
AUREQUIRE FALSE, TRUE or TRY <node>

Practical considerations

Enabling this for alarms would be burdensome in most environments.

CSS

Determine whether enabling of alarms or audits for CSS event conforms to policy.

Violation reports

Constraint Nature of the violation
ALPROHIBIT CSS security alarms are enabled in violation of policy
ALREQUIRE CSS security alarms are disabled in violation of policy
AUPROHIBIT CSS security audits are enabled in violation of policy
AUREQUIRE CSS security audits are disabled in violation of policy

Description

As of V7.3 VMS does not provide a method to enable auditing or alarms for these events.

Default policy

Enabling of CSS security alarms and audits is neither prohibited nor required

Customizing

Set limits TRUE to establish a general prohibition of or requirement for the enabling of CSS security alarms or audits. Then establish exemptions for any individual nodes which are not to be subjected to the general rule. selector

Limits

Constraint Value Default
ALPROHIBIT FALSE or TRUE FALSE
ALREQUIRE FALSE, TRUE or TRY FALSE
AUPROHIBIT FALSE or TRUE FALSE
AUREQUIRE FALSE, TRUE or TRY FALSE

Exemptions

Constraint Value Parameters
ALPROHIBIT FALSE or TRUE <node>
ALREQUIRE FALSE, TRUE or TRY <node>
AUPROHIBIT FALSE or TRUE <node>
AUREQUIRE FALSE, TRUE or TRY <node>

Practical considerations

As of V7.3 VMS does not provide a method to enable auditing or alarms for these events.

CUSTOMER

Determine whether enabling of alarms or audits for customer event conforms to policy.

Violation reports

Constraint Nature of the violation
ALPROHIBIT Customer security alarms are enabled in violation of policy
ALREQUIRE Customer security alarms are disabled in violation of policy
AUPROHIBIT Customer security audits are enabled in violation of policy
AUREQUIRE Customer security audits are disabled in violation of policy

Description

As of V7.3 VMS does not provide a method to enable auditing or alarms for these events.

Default policy

Enabling of Customer security alarms and audits is neither prohibited nor required

Customizing

Set limits TRUE to establish a general prohibition of or requirement for the enabling of Customer security alarms or audits. Then establish exemptions for any individual nodes which are not to be subjected to the general rule. selector

Limits

Constraint Value Default
ALPROHIBIT FALSE or TRUE FALSE
ALREQUIRE FALSE, TRUE or TRY FALSE
AUPROHIBIT FALSE or TRUE FALSE
AUREQUIRE FALSE, TRUE or TRY FALSE

Exemptions

Constraint Value Parameters
ALPROHIBIT FALSE or TRUE <node>
ALREQUIRE FALSE, TRUE or TRY <node>
AUPROHIBIT FALSE or TRUE <node>
AUREQUIRE FALSE, TRUE or TRY <node>

Practical considerations

As of V7.3 VMS does not provide a method to enable auditing or alarms for these events.

DOWNGRADE

Determine whether auditing for events involving the use of DOWNGRADE privilege conforms to policy.

Violation reports

Constraint Nature of the violation
ALPROHIBIT DOWNGRADE security alarms are enabled in violation of policy
ALREQUIRE DOWNGRADE security alarms are disabled in violation of policy
AUPROHIBIT DOWNGRADE security audits are enabled in violation of policy
AUREQUIRE DOWNGRADE security audits are disabled in violation of policy

Description

Use of the qualifiers /CLASS=FILE and
/ENABLE=ACCESS=DOWNGRADE=(access,...) with the SET AUDIT/ALARM or SET AUDIT/AUDIT command causes the corresponding reporting when DOWNGRADE privilege is used to obtain the specified type of access to files. Tests for this element determine whether those audits or alarms are enabled or not.

SEVMS required

The (AUDIT, DOWNGRADE, ALREQUIRE) and ((AUDIT, DOWNGRADE, AUREQUIRE) tests will never report an error on systems that do not have the CLASS_PROT system parameter enabled. When the CLASS_PROT system parameter is not enabled, audits and alarms for use of the DOWNGRADE privilege cannot be enabled.

If the policy covering a number of systems is to require that the SEVMS product be used, the test (VMS, CLASSPROT, REQUIRED) should be used.

Default policy

Enabling of DOWNGRADE security alarms or audits is neither prohibited nor required

Customizing

Set limits TRUE to establish a general prohibition of or requirement for the enabling of DOWNGRADE security auditing. Then establish exemptions for any individual nodes which are not to be subjected to the general rule. selector Limits for this element can take a selector consisting of a VMS access type: READ, WRITE, EXECUTE, DELETE or CONTROL. LOGICAL and PHYSICAL access to devices are indicated by EXECUTE and DELETE respectively.

Thus, each limit can be set once for each possible access type. If you do not specify a selector when changing limits, your change applies to all access types.

Limits

Constraint Value Default
ALPROHIBIT FALSE or TRUE FALSE
ALREQUIRE FALSE or TRUE FALSE
AUPROHIBIT FALSE or TRUE FALSE
AUREQUIRE FALSE or TRUE FALSE

Exemptions

Constraint Value Parameters
ALPROHIBIT FALSE or TRUE <node>
ALREQUIRE FALSE or TRUE <node>
AUPROHIBIT FALSE or TRUE <node>
AUREQUIRE FALSE or TRUE <node>

Practical considerations

The DOWNGRADE privilege is only relevant to systems running Mandatory Access Controls, as implemented with the SEVMS (Security Enhanced VMS) software available from DEC.

DOWNGRADE audits and alarms may both be quite appropriate in such environments since such activities are rare and worthy of note.


FAILCRASH

Determine whether specification of system crash when security alarms cannot be generated conforms to policy.

Violation reports

Constraint Nature of the violation
PROHIBITED Crash on failure is specified in violation of policy
REQUIRED Crash on failure is not specified in violation of policy

Description

Use of the qualifier /FAILURE_MODE=CRASH with the SET AUDIT command causes the system to crash when security alarms cannot be written to the OPCOM mailbox (only in VMS V5.4 through V5.5).

Default policy

Specification of CRASH as the failure mode is neither prohibited nor required

Customizing

Set limits TRUE to establish a general prohibition of or requirement for system crash as the failure mode for security alarms. Then establish exemptions for any individual nodes which are not to be subjected to the general rule.

Set limit REQUIRED TRY to establish a requirement for system crash as the failure mode only for those versions of VMS (version 5.4 through 5.5) where such failure modes are supported. selector

Limits

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

Exemptions

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

Practical considerations

If individual users have sufficient disk quota to exhaust disk space on the volume where OPCOM logs are written, they can force a system crash if CRASH is the failure mode for security alarms.

Likewise, if the amount of disk space available for writing OPCOM logs is small, individual users could force a system crash by maliciously generating a large number of security alarms.

These possibilities for malicious interference increase the importance of ensuring that all usernames established on VMS systems are assigned to known individual users, rather than being shared.


FAILIGNORE

Determine whether specification of no action when security alarms cannot be generated conforms to policy.

Violation reports

Constraint Nature of the violation
PROHIBITED No action on failure is specified in violation of policy
REQUIRED No action on failure is not specified in violation of policy

Description

Use of the qualifier /FAILURE_MODE=IGNORE with the SET AUDIT command causes no action to be taken when security alarms cannot be written to the OPCOM mailbox (only in VMS V5.4 through V5.5).

Default policy

Specification of IGNORE as the failure mode is neither prohibited nor required

Customizing

Set limits TRUE to establish a general prohibition of or requirement for no action as the failure mode for security alarms. Then establish exemptions for any individual nodes which are not to be subjected to the general rule.

Set limit PROHIBITED TRY to establish a prohibition against ignoring as the failure mode only for those versions of VMS (version 5.4 through 5.5) where other failure modes are supported. selector

Limits

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

Exemptions

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

Practical considerations

IGNORE provides the best continuity of service in the event that disk space is exhausted on the volume where the OPCOM logs are written.

FAILURE

Determine whether auditing for access failure events conforms to policy.

Violation reports

Constraint Nature of the violation
ALPROHIBIT FAILURE security alarms are enabled in violation of policy
ALREQUIRE FAILURE security alarms are disabled in violation of policy
AUPROHIBIT FAILURE security audits are enabled in violation of policy
AUREQUIRE FAILURE security audits are disabled in violation of policy

Description

Use of the qualifiers /CLASS=FILE and
/ENABLE=ACCESS=FAILURE=(access,...) with the SET AUDIT/ALARM or SET AUDIT/AUDIT command causes the corresponding reporting when access attempts to files fail. Tests for this element determine whether those audits or alarms are enabled or not.

Default policy

Enabling of FAILURE security alarms or audits is neither prohibited nor required

Customizing

Set limits TRUE to establish a general prohibition of or requirement for the enabling of FAILURE security auditing. Then establish exemptions for any individual nodes which are not to be subjected to the general rule. selector Limits for this element can take a selector consisting of a VMS access type: READ, WRITE, EXECUTE, DELETE or CONTROL. LOGICAL and PHYSICAL access to devices are indicated by EXECUTE and DELETE respectively.

Thus, each limit can be set once for each possible access type. If you do not specify a selector when changing limits, your change applies to all access types.

Limits

Constraint Value Default
ALPROHIBIT FALSE or TRUE FALSE
ALREQUIRE FALSE or TRUE FALSE
AUPROHIBIT FALSE or TRUE FALSE
AUREQUIRE FALSE or TRUE FALSE

Exemptions

Constraint Value Parameters
ALPROHIBIT FALSE or TRUE <node>
ALREQUIRE FALSE or TRUE <node>
AUPROHIBIT FALSE or TRUE <node>
AUREQUIRE FALSE or TRUE <node>

Practical considerations

Enabling FAILURE security alarms and audits will cause a certain number of false alarms due to typing errors and similar mistakes. Making effective use of FAILURE security alarms and audits requires a willingness to sort through the incidental errors looking for those errors which represent a coordinated attack.


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