TCP/IP resources must be properly protected.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-3219	ITCP0050	SV-7084r4_rule		Medium

Description
The Communication Server access authorization is used to protect TCP/IP resources such as stack, network, port, and other SERVAUTH resources. These resources provide additional security checks for TCP/IP users. Failure to properly secure these TCP/IP resources could lead to unauthorized user access resulting in the compromise of some system services and possible compromise of data.

STIG	Date
z/OS TSS STIG	2018-04-04

Details

Check Text ( C-20730r5_chk )
Refer to the following report produced by the TSS Data Collection and Data Set and Resource Data Collection: - SENSITVE.RPT(ITCP0050) Automated Analysis Refer to the following report produced by the Data Set and Resource Data Collection: - PDI(ITCP0050) Ensure that all TCP/IP resources and/or generic equivalent are properly protected according to the requirements specified. If the following guidance is true, this is not a finding. ___ The EZA, EZB, and IST resources of the SERVAUTH resource class are properly owned and/or DEFPROT is specified in the SERVAUTH resource class. ___ No access is given to the EZA, EZB, and IST high level resources of the SERVAUTH resource class. ___ If the product CSSMTP is on the system, no access is given to EZB.CSSMTP of the SERVAUTH resource class. ___ If the product CSSMTP is on the system, EZB.CSSMTP.sysname.writername.JESnode will be specified and made available to the CSSMTP started task and authenticated users that require access to use CSSMTP for e-mail services. ___ Authenticated users that require access will be permitted access to the second level of the resources in the SERVAUTH resource class. Examples are the network (NETACCESS), port (PORTACCESS), stack (STACKACCESS), and FTP resources in the SERVAUTH resource class. ___ The EZB.STACKACCESS. resource access authorizations restrict access to those started tasks with valid requirements and users with valid FTP access requirements. ___ The EZB.FTP...ACCESS.HFS) resource access authorizations restrict access to FTP users with specific written documentation showing a valid requirement exists to access OMVS files and Directories.

Check Text ( C-20730r5_chk )

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

- SENSITVE.RPT(ITCP0050)

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

- PDI(ITCP0050)

Ensure that all TCP/IP resources and/or generic equivalent are properly protected according to the requirements specified. If the following guidance is true, this is not a finding.

___ The EZA, EZB, and IST resources of the SERVAUTH resource class are properly owned and/or DEFPROT is specified in the SERVAUTH resource class.

___ No access is given to the EZA, EZB, and IST high level resources of the SERVAUTH resource class.

___ If the product CSSMTP is on the system, no access is given to EZB.CSSMTP of the SERVAUTH resource class.

___ If the product CSSMTP is on the system, EZB.CSSMTP.sysname.writername.JESnode will be specified and made available to the CSSMTP started task and authenticated users that require access to use CSSMTP for e-mail services.

___ Authenticated users that require access will be permitted access to the second level of the resources in the SERVAUTH resource class. Examples are the network (NETACCESS), port (PORTACCESS), stack (STACKACCESS), and FTP resources in the SERVAUTH resource class.

___ The EZB.STACKACCESS. resource access authorizations restrict access to those started tasks with valid requirements and users with valid FTP access requirements.

___ The EZB.FTP.*.*.ACCESS.HFS) resource access authorizations restrict access to FTP users with specific written documentation showing a valid requirement exists to access OMVS files and Directories.

Fix Text (F-28876r2_fix)
The IAO must develop a plan of action to implement the required changes. Ensure the following items are in effect for TCP/IP resources. (Note: The resource class, resources, and/or resource prefixes identified below are examples of a possible installation. The actual resource class, resources, and/or resource prefixes are determined when the product is actually installed on a system through the product’s installation guide and can be site specific.) Ensure that the EZA, EZB, and IST resources of the SERVAUTH resource class are properly owned and/or DEFPROT is specified in the SERVAUTH resource class. No access is given to the EZA, EZB, and IST resources of the SERVAUTH resource class. If the product CSSMTP is on the system, no access is given to EZB.CSSMTP of the SERVAUTH resource class. EZB.CSSMTP.sysname.writername.JESnode will be specified and made available to the CSSMTP started task and authenticated users that require access to use CSSMTP for e-mail services. Only authenticated users that require access are permitted access to the second level of the resources in the SERVAUTH resource class. Examples are the network (NETACCESS), port (PORTACCESS), stack (STACKACCESS), and FTP resources in the SERVAUTH resource class. The EZB.STACKACCESS. resource access authorizations restrict access to those started tasks with valid requirements and users with valid FTP access requirements. The EZB.FTP...ACCESS.HFS) resource access authorizations restrict access to FTP users with specific written documentation showing a valid requirement exists to access OMVS files and Directories. The following commands are provided as a sample for implementing resource controls: TSS ADD(ADMIN) SERVAUTH(EZB) or TSS REPLACE(RDT) RESCLASS(SERVAUTH) ATTR(DEFPROT) TSS PER(authusers) SERVAUTH(EZB.CSSMTP.sysname.writername.JESnode) ACCESS(READ) TSS PER(authusers) SERVAUTH(EZB.FTP.) ACCESS(READ) TSS PER(ftpprofile)SERVAUTH(EZB.FTP.sysname.ftpstc.ACCESS.HFS)ACC(READ) TSS PER(authusers) SERVAUTH(EZB.NETACCESS.) ACCESS(READ) TSS PER(authusers) SERVAUTH(EZB.PORTACCESS.) ACCESS(READ) TSS PER(authusers) SERVAUTH(EZB.STACKACCESS.) ACCESS(READ) TSS PER(ftpprofile)SERVAUTH(EZB.STACKACCESS.sysname.TCPIP)ACC(READ) The following notes apply to these controls: - According to Computer Associates’ Security Cookbook for eTrust CA TOP SECRET, access to stack (EZB.STACKACCESS) resources will be given to ACIDs that require it. As a result, adequate access definitions for stack resources are critical to proper system availability. EZB.STACKACCESS.sysname.TCPIP access READ should be limited to only those started tasks that require access to the TCPIP Stack as well as any users approved for FTP Access (inbound and/or outbound). FTP users should not have access to the EZB.FTP.sysname.ftpstc.ACCESS.HFS resource unless specific written justification documenting valid requirement for those FTP users to access USS files and directories via FTP. - To be effective in restricting access, the network (EZB.NETACCESS) resource control requires configuration of the NETACCESS statement in the PROFILE.TCPIP file. - To be effective in restricting access, the port (EZB.PORTACCESS) resource control requires configuration of a PORT or PORTRANGE statement in the PROFILE.TCPIP file. These port definitions within PROFILE.TCPIP shall be defined to include SAF keyword and a valid name. A list of possible SERVAUTH resources defined to the first two nodes is shown here: (Note that additional resources may be developed with each new release of TCPIP.) EZA.DCAS. EZB.BINDDVIPARANGE. EZB.CIMPROV. EZB.FRCAACCESS. EZB.FTP. EZB.INITSTACK. EZB.IOCTL. EZB.IPSECCMD. EZB.MODDVIPA. EZB.NETACCESS. EZB.NETMGMT. EZB.NETSTAT. EZB.NSS. EZB.NSSCERT. EZB.OSM. EZB.PAGENT. EZB.PORTACCESS. EZB.RPCBIND. EZB.SOCKOPT. EZB.SNMPAGENT. EZB.STACKACCESS. EZB.TN3270. IST.NETMGMT.

Fix Text (F-28876r2_fix)

The IAO must develop a plan of action to implement the required changes. Ensure the following items are in effect for TCP/IP resources.

(Note: The resource class, resources, and/or resource prefixes identified below are examples of a possible installation. The actual resource class, resources, and/or resource prefixes are determined when the product is actually installed on a system through the product’s installation guide and can be site specific.)

Ensure that the EZA, EZB, and IST resources of the SERVAUTH resource class are properly owned and/or DEFPROT is specified in the SERVAUTH resource class.

No access is given to the EZA, EZB, and IST resources of the SERVAUTH resource class.

If the product CSSMTP is on the system, no access is given to EZB.CSSMTP of the SERVAUTH resource class. EZB.CSSMTP.sysname.writername.JESnode will be specified and made available to the CSSMTP started task and authenticated users that require access to use CSSMTP for e-mail services.

Only authenticated users that require access are permitted access to the second level of the resources in the SERVAUTH resource class. Examples are the network (NETACCESS), port (PORTACCESS), stack (STACKACCESS), and FTP resources in the SERVAUTH resource class.

The EZB.STACKACCESS. resource access authorizations restrict access to those started tasks with valid requirements and users with valid FTP access requirements.

The EZB.FTP.*.*.ACCESS.HFS) resource access authorizations restrict access to FTP users with specific written documentation showing a valid requirement exists to access OMVS files and Directories.

The following commands are provided as a sample for implementing resource controls:

TSS ADD(ADMIN) SERVAUTH(EZB)
or
TSS REPLACE(RDT) RESCLASS(SERVAUTH) ATTR(DEFPROT)

TSS PER(authusers) SERVAUTH(EZB.CSSMTP.sysname.writername.JESnode) ACCESS(READ)
TSS PER(authusers) SERVAUTH(EZB.FTP.) ACCESS(READ)
TSS PER(ftpprofile)SERVAUTH(EZB.FTP.sysname.ftpstc.ACCESS.HFS)ACC(READ)
TSS PER(authusers) SERVAUTH(EZB.NETACCESS.) ACCESS(READ)
TSS PER(authusers) SERVAUTH(EZB.PORTACCESS.) ACCESS(READ)
TSS PER(authusers) SERVAUTH(EZB.STACKACCESS.) ACCESS(READ)
TSS PER(ftpprofile)SERVAUTH(EZB.STACKACCESS.sysname.TCPIP)ACC(READ)

The following notes apply to these controls:

- According to Computer Associates’ Security Cookbook for eTrust CA TOP SECRET, access to stack (EZB.STACKACCESS) resources will be given to ACIDs that require it. As a result, adequate access definitions for stack resources are critical to proper system availability. EZB.STACKACCESS.sysname.TCPIP access READ should be limited to only those started tasks that require access to the TCPIP Stack as well as any users approved for FTP Access (inbound and/or outbound). FTP users should not have access to the EZB.FTP.sysname.ftpstc.ACCESS.HFS resource unless specific written justification documenting valid requirement for those FTP users to access USS files and directories via FTP.

- To be effective in restricting access, the network (EZB.NETACCESS) resource control requires configuration of the NETACCESS statement in the PROFILE.TCPIP file.

- To be effective in restricting access, the port (EZB.PORTACCESS) resource control requires configuration of a PORT or PORTRANGE statement in the PROFILE.TCPIP file. These port definitions within PROFILE.TCPIP shall be defined to include SAF keyword and a valid name.

A list of possible SERVAUTH resources defined to the first two nodes is shown here: (Note that additional resources may be developed with each new release of TCPIP.)

EZA.DCAS.
EZB.BINDDVIPARANGE.
EZB.CIMPROV.
EZB.FRCAACCESS.
EZB.FTP.
EZB.INITSTACK.
EZB.IOCTL.
EZB.IPSECCMD.
EZB.MODDVIPA.
EZB.NETACCESS.
EZB.NETMGMT.
EZB.NETSTAT.
EZB.NSS.
EZB.NSSCERT.
EZB.OSM.
EZB.PAGENT.
EZB.PORTACCESS.
EZB.RPCBIND.
EZB.SOCKOPT.
EZB.SNMPAGENT.
EZB.STACKACCESS.
EZB.TN3270.
IST.NETMGMT.