Write or greater access to Libraries containing EXIT modules must be limited to system programmers only.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-129	ACP00240	SV-129r3_rule	DCCS-1 DCCS-2 DCSL-1	High

Description
System exits have a wide range of uses and capabilities within any system. Exits may introduce security exposures within the system, modify audit trails, and alter individual user capabilities. Unauthorized access could result in the compromise of the operating system environment, ACP, and customer data.

STIG	Date
z/OS TSS STIG	2019-09-27

Details

Check Text ( C-5030r1_chk )
a) Refer to the following report produced by the Data Set and Resource Data Collection: - SENSITVE.RPT(MVSXRPT) Automated Analysis Refer to the following report produced by the Data Set and Resource Data Collection: - PDI(ACP00240) ___ The ACP data set rules for libraries that contain exit modules allow inappropriate access. ___ The ACP data set rules for libraries that contain system exit modules do not restrict UPDATE and ALLOCATE access to only z/OS systems programming personnel. ___ The ACP data set rules for libraries that contain exit modules do not specify that all UPDATE and ALLOCATE access will be logged. b) If all of the above are untrue, there is NO FINDING. c) If any of the above is true, this is a FINDING.

Check Text ( C-5030r1_chk )

a) Refer to the following report produced by the Data Set and Resource Data Collection:

- SENSITVE.RPT(MVSXRPT)

Automated Analysis
Refer to the following report produced by the Data Set and Resource Data Collection:

- PDI(ACP00240)

___ The ACP data set rules for libraries that contain exit modules allow inappropriate access.

___ The ACP data set rules for libraries that contain system exit modules do not restrict UPDATE and ALLOCATE access to only z/OS systems programming personnel.

___ The ACP data set rules for libraries that contain exit modules do not specify that all UPDATE and ALLOCATE access will be logged.

b) If all of the above are untrue, there is NO FINDING.

c) If any of the above is true, this is a FINDING.

Fix Text (F-17496r1_fix)
Using the ACP, protect the data sets associated with all product exits installed in the z/OS environment. This reduces the potential of a hacker adding a routine to a library and possibly creating an exposure. See that all exits are tracked using a CMP. Develop usermods to include the source/object code used to support the exits. Have Systems programming personnel review all z/OS and other product exits to confirm that the exits are required and are correctly installed. Have the IAO validate that all update and alter access to libraries containing z/OS and other system level exits will be logged using the ACP’s facilities. Only systems programming personnel will be authorized to update the libraries containing z/OS and other system level exits.

Fix Text (F-17496r1_fix)

Using the ACP, protect the data sets associated with all product exits installed in the z/OS environment. This reduces the potential of a hacker adding a routine to a library and possibly creating an exposure. See that all exits are tracked using a CMP. Develop usermods to include the source/object code used to support the exits. Have Systems programming personnel review all z/OS and other product exits to confirm that the exits are required and are correctly installed.

Have the IAO validate that all update and alter access to libraries containing z/OS and other system level exits will be logged using the ACP’s facilities. Only systems programming personnel will be authorized to update the libraries containing z/OS and other system level exits.