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IBM RACF exit ICHPWX11 must be installed and properly configured.


Finding ID Version Rule ID IA Controls Severity
V-230210 RACF-ES-000785 SV-230210r768722_rule Medium
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.
IBM z/OS RACF Security Technical Implementation Guide 2022-09-19


Check Text ( C-32543r768720_chk )
From a system console screen issue the following modify command:

Review the results of the modify command.

If all of 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 is not contained in the password phrase
(Only 3 consecutive characters of the user's name are allowed)

-The minimum password phrase length checked is 15

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

-The new password phrase is at least 50% changed positions of the old password phrase.
(These positions need to be consecutive to cause a failure and this check is not case sensitive)

-A minimum list of 8 restricted words are being checked:

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-32519r768721_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

Phr_minlen = 15 /* Minimum length */
Phr_maxlen = 100 /* Maximum passphrase length */
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_userid_allowed = 'no'
Phr_req_types = 4
Phr_min_unique = Phr_minlen % 2 /* 'Half' of chars must be unique */
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.