IBM RACF exit ICHPWX11 must be installed and properly configured.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-230210	RACF-ES-000785	SV-230210r562975_rule		Medium

Description
Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.

Description

Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that need to be tested before the password is compromised.

STIG	Date
IBM z/OS RACF Security Technical Implementation Guide	2020-10-09

Details

Check Text ( C-32543r561117_chk )
From a system console screen issue the following modify command: F AXR,IRRPHREX LIST Review the results of the modify command. If the following options are listed, this is not a finding. -The number of required character types is 4 (assures that at least 1 upper case, 1 lower case, 1 number, and 1 special character is used in Password phrase) -The user's name cannot be contained in the password phrase (Only 3 consecutive characters of the user's name are allowed) -The minimum word length checked is 15 -The user ID cannot be contained in the password phrase (Only 3 consecutive characters of the user ID are allowed) -At least half of unchanged positions of the current password phrase are allowed (These positions need to be consecutive to cause a failure and this check is not case sensitive) -A minimum list of 8 restricted prefix strings is being checked: 'IBM' ,'RACF','PASSWORD','PHRASE','PASSPHRAS’,'SECRET','IBMUSER','SYS1' If the modify command fails or returns the following message in the system log, this is a finding. IRX0406E REXX exec load file REXXLIB does not contain exec member IRRPHREX.

Check Text ( C-32543r561117_chk )

From a system console screen issue the following modify command:
F AXR,IRRPHREX LIST

Review the results of the modify command.

If the following options are listed, this is not a finding.

-The number of required character types is 4
(assures that at least 1 upper case, 1 lower case, 1 number, and 1 special character is used in Password phrase)

-The user's name cannot be contained in the password phrase
(Only 3 consecutive characters of the user's name are allowed)

-The minimum word length checked is 15

-The user ID cannot be contained in the password phrase
(Only 3 consecutive characters of the user ID are allowed)

-At least half of unchanged positions of the current password phrase are allowed
(These positions need to be consecutive to cause a failure and this check is not case sensitive)

-A minimum list of 8 restricted prefix strings is being checked:
'IBM' ,'RACF','PASSWORD','PHRASE','PASSPHRAS’,'SECRET','IBMUSER','SYS1'

If the modify command fails or returns the following message in the system log, this is a finding.

IRX0406E REXX exec load file REXXLIB does not contain exec member IRRPHREX.

Fix Text (F-32519r561118_fix)
Evaluate the impact associated with implementation of the control option. Develop a plan of action to implement the control option as specified in the example below: For z/OS release 1.12 through z/OS release 2.1 APARs OA43998 and OA43999 must be applied. Install exit IRRPHREX according to the following guidelines: REXX Parameter Setting /* DISA Modifications: / / 15DEC2017 HC: Added "special = '$@#.\|&!-%_:='" / /* : Changed Phr_minlen = 9 to Phr_minlen = 15 / / : Turned on options to disallow leading and trailing / / : blanks. / / : Added check to ensure 1 of each Upper Lower Numeric / / : and Special ... NOTE THAT an imbedded blank is / / : considered a Special character / / : Added check for repeating characters, no more than / / : one occurrence in any case e.g. aa aA AA / / : Added check to ensure userid is not contained / / : anywhere in the phrase / Phr_minlen = 15 / Minimum length is Phr_maxlen = 100 /* Maximum passwor numbers = '0123456789' letters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ' special = '$@#.\|&!*-%_:='" Phr_allowed_chars = numbers\|\|letters\|\|special Phr_leading_blanks = 'no' Phr_trailing_blanks = 'no' Phr_name_allowed = 'no' Phr_name_minlen = 3 Phr_repeat_chars_chk = 'yes' Phr_repeat_chars = 1 Phr_userid_allowed = 'no' Phr_req_types = 4 Phr_triviality = 'yes’ Phr_min_unique = 7 Phr_min_unique_norm = 'yes' Phr_word_unique = 0 Phr_word_unique_upper = 'yes' Phr_word_minlen = 4 Phr_dict.1 = 'IBM' Phr_dict.2 = 'RACF' Phr_dict.3 = 'PASSWORD' Phr_dict.4 = 'PHRASE' Phr_dict.5 = 'PASSPHRAS Phr_dict.6 = 'SECRET' Phr_dict.7 = 'IBMUSER' Phr_dict.8 = 'SYS1' Note: RACF exit ICHPHX11 is coded to call a System REXX named IRRPHREX, so the name cannot be changed without a corresponding change to ICHPWX11. System REXX requires that this exec (IRRPHREX) reside in the REXXLIB concatenation. Update parameters in IRRPHREX according to table Parameters for RACF IRRPWREX as listed above.

Fix Text (F-32519r561118_fix)

Evaluate the impact associated with implementation of the control option. Develop a plan of action to implement the control option as specified in the example below:

For z/OS release 1.12 through z/OS release 2.1 APARs OA43998 and OA43999 must be applied.

Install exit IRRPHREX according to the following guidelines:
REXX Parameter Setting

/* DISA Modifications: */
/* 15DEC2017 HC: Added "special = '$@#.|&!*-%_:='" */
/* : Changed Phr_minlen = 9 to Phr_minlen = 15 */
/* : Turned on options to disallow leading and trailing */
/* : blanks. */
/* : Added check to ensure 1 of each Upper Lower Numeric */
/* : and Special ... NOTE THAT an imbedded blank is */
/* : considered a Special character */
/* : Added check for repeating characters, no more than */
/* : one occurrence in any case e.g. aa aA AA */
/* : Added check to ensure userid is not contained */
/* : anywhere in the phrase */
Phr_minlen = 15 /* Minimum length is
Phr_maxlen = 100 /* Maximum passwor
numbers = '0123456789'
letters = 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
special = '$@#.|&!*-%_:='"
Phr_allowed_chars = numbers||letters||special
Phr_leading_blanks = 'no'
Phr_trailing_blanks = 'no'
Phr_name_allowed = 'no'
Phr_name_minlen = 3
Phr_repeat_chars_chk = 'yes'
Phr_repeat_chars = 1
Phr_userid_allowed = 'no'
Phr_req_types = 4
Phr_triviality = 'yes’
Phr_min_unique = 7
Phr_min_unique_norm = 'yes'
Phr_word_unique = 0
Phr_word_unique_upper = 'yes'
Phr_word_minlen = 4
Phr_dict.1 = 'IBM'
Phr_dict.2 = 'RACF'
Phr_dict.3 = 'PASSWORD'
Phr_dict.4 = 'PHRASE'
Phr_dict.5 = 'PASSPHRAS
Phr_dict.6 = 'SECRET'
Phr_dict.7 = 'IBMUSER'
Phr_dict.8 = 'SYS1'

Note: RACF exit ICHPHX11 is coded to call a System REXX named IRRPHREX, so the name cannot be changed without a corresponding change to ICHPWX11.

System REXX requires that this exec (IRRPHREX) reside in the REXXLIB concatenation.

Update parameters in IRRPHREX according to table Parameters for RACF IRRPWREX as listed above.