User exits for the FTP Server must not be used without proper approval and documentation.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-3236	IFTP0040	SV-3236r3_rule		Medium

Description
Several user exit points in the FTP Server component are available to permit customization of its operating behavior. These exits can be used to modify functions such as FTP command usage, client connection controls, post processing tasks, and SMF record modifications. Without proper review and adequate documentation of these exit programs, undesirable operations and degraded security may result. This exposure could lead to unauthorized access impacting data integrity or the availability of some system services, or contribute to the loss of accountability and hamper security audit activities.

Description

Several user exit points in the FTP Server component are available to permit customization of its operating behavior. These exits can be used to modify functions such as FTP command usage, client connection controls, post processing tasks, and SMF record modifications. Without proper review and adequate documentation of these exit programs, undesirable operations and degraded security may result. This exposure could lead to unauthorized access impacting data integrity or the availability of some system services, or contribute to the loss of accountability and hamper security audit activities.

STIG	Date
z/OS TSS STIG	2018-10-04

Details

Check Text ( C-2741r2_chk )
a) Refer to the Data configuration file specified on the SYSFTPD DD statement in the FTP started task JCL. Refer to the file(s) allocated by the STEPLIB DD statement in the FTP started task JCL. Refer to the libraries specified in the system Linklist and LPA. If any FTP Server exits are in use, identify them and validate that they were reviewed for integrity and approved by the site AO. b) Ensure the following items are in effect for FTP Server user exits: The FTCHKCMD, FTCHKIP, FTCHKJES, FTCHKPWD, FTPSMFEX and FTPOSTPR modules are not located in the FTP daemon’s STEPLIB, Linklist, or LPA. NOTE: The ISPF ISRFIND utility can be used to search the system Linklist and LPA for specific modules. c) If both of the above are true, there is no finding. d) If any FTP Server user exits are implemented and the site has written approval from site ISSM to install and use the exits, there is no finding. e) If any FTP Server user exits are implemented and the site has not had the site systems programmer verify the exit was securely written and installed, this is a finding.

Check Text ( C-2741r2_chk )

a) Refer to the Data configuration file specified on the SYSFTPD DD statement in the FTP started task JCL.

Refer to the file(s) allocated by the STEPLIB DD statement in the FTP started task JCL.

Refer to the libraries specified in the system Linklist and LPA.

If any FTP Server exits are in use, identify them and validate that they were reviewed for integrity and approved by the site AO.

b) Ensure the following items are in effect for FTP Server user exits:

The FTCHKCMD, FTCHKIP, FTCHKJES, FTCHKPWD, FTPSMFEX and FTPOSTPR modules are not located in the FTP daemon’s STEPLIB, Linklist, or LPA.

NOTE: The ISPF ISRFIND utility can be used to search the system Linklist and LPA for specific modules.

c) If both of the above are true, there is no finding.

d) If any FTP Server user exits are implemented and the site has written approval from site ISSM to install and use the exits, there is no finding.

e) If any FTP Server user exits are implemented and the site has not had the site systems programmer verify the exit was securely written and installed, this is a finding.

Fix Text (F-18160r2_fix)
Review the configuration statements in the FTP.DATA file. Review the FTP daemon STEPLIB, system Linklist, and Link Pack Area libraries. If FTP Server exits are enabled or present, and have not been approved by the site IAM and not securely written and implemented by the site systems programmer, they should not be installed. Verify that non of the following exits are installed unless they have met the requirements listed above: FTCHKCMD FTCHKIP FTCHKJES FTCHKPWD FTPOSTPR FTPSMFEX

Fix Text (F-18160r2_fix)

Review the configuration statements in the FTP.DATA file. Review the FTP daemon STEPLIB, system Linklist, and Link Pack Area libraries. If FTP Server exits are enabled or present, and have not been approved by the site IAM and not securely written and implemented by the site systems programmer, they should not be installed. Verify that non of the following exits are installed unless they have met the requirements listed above:
FTCHKCMD
FTCHKIP
FTCHKJES
FTCHKPWD
FTPOSTPR
FTPSMFEX