IBM z/OS SNTP daemon (SNTPD) must be active.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-223552	ACF2-OS-000160	SV-223552r533198_rule		Medium

Description
Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time, a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. Organizations should consider endpoints that may not have regular access to the authoritative time server (e.g., mobile, teleworking, and tactical endpoints).

Description

Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time, a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. Organizations should consider endpoints that may not have regular access to the authoritative time server (e.g., mobile, teleworking, and tactical endpoints).

STIG	Date
IBM z/OS ACF2 Security Technical Implementation Guide	2021-03-29

Details

Check Text ( C-25225r504689_chk )
Verify the operating system, for networked systems, compares internal information system clocks at least every 24 hours with a server which is synchronized to one of the redundant United States Naval Observatory (USNO) time servers, or a time server designated for the appropriate DoD network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS). If it does not, this is a finding.

Fix Text (F-25213r504690_fix)
Obtain a copy of this sample procedure from SEZAINST and store it in one of your PROCLIB concatenation data sets. Perform the following step to start SNTPD as a procedure: Invoke the procedure using the system operator start command. The following sample, SEZAINST(SNTPD), shows how to start SNTPD as a procedure: //* //* Sample procedure for the Simple Network Time Protocol (SNTP) //* //* z/OS Communications Server Version 1 Release 13 //* SMP/E Distribution Name: SEZAINST(EZASNPRO) //* //* Copyright: Licensed Materials - Property of IBM //* 5650-ZOS //* Copyright IBM Corp. 2002, 2015 //* //* Status: CSV2R2 //* //SNTPD EXEC PGM=SNTPD,REGION=4096K,TIME=NOLIMIT, //PARM=’/ -d’ //SYSPRINT DD SYSOUT=,DCB=(RECFM=F,LRECL=132,BLKSIZE=132) //SYSIN DD DUMMY //SYSERR DD SYSOUT= //SYSOUT DD SYSOUT=,DCB=(RECFM=F,LRECL=132,BLKSIZE=132) //CEEDUMP DD SYSOUT= //SYSABEND DD SYSOUT=*

Fix Text (F-25213r504690_fix)

Obtain a copy of this sample procedure from SEZAINST and store it in one of your PROCLIB concatenation data sets.

Perform the following step to start SNTPD as a procedure:
Invoke the procedure using the system operator start command. The following sample, SEZAINST(SNTPD), shows how to start SNTPD as a procedure:
//*
//* Sample procedure for the Simple Network Time Protocol (SNTP)
//*
//* z/OS Communications Server Version 1 Release 13
//* SMP/E Distribution Name: SEZAINST(EZASNPRO)
//*
//* Copyright: Licensed Materials - Property of IBM
//* 5650-ZOS
//* Copyright IBM Corp. 2002, 2015
//*
//* Status: CSV2R2
//*
//SNTPD EXEC PGM=SNTPD,REGION=4096K,TIME=NOLIMIT,
//PARM=’/ -d’
//SYSPRINT DD SYSOUT=*,DCB=(RECFM=F,LRECL=132,BLKSIZE=132)
//SYSIN DD DUMMY
//SYSERR DD SYSOUT=*
//SYSOUT DD SYSOUT=*,DCB=(RECFM=F,LRECL=132,BLKSIZE=132)
//CEEDUMP DD SYSOUT=*
//SYSABEND DD SYSOUT=*