STIGUI
V-271618CAT II — Medium severitySV-271618r1091566_rule

OL 9 must require the maximum number of repeating characters of the same character class be limited to four when passwords are changed.

Rule version OL09-00-001030 · STIG v1 · 2026-08-21

Discussion

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 a password, the greater the number of possible combinations that need to be tested before the password is compromised.

Check

Verify that OL 9 requires the maximum number of repeating characters of the same character class be limited to four when passwords are changed.

Verify the value of the "maxclassrepeat" option in "/etc/security/pwquality.conf" with the following command:

$ grep maxclassrepeat /etc/security/pwquality.conf /etc/security/pwquality.conf.d/*.conf maxclassrepeat = 4

If the value of "maxclassrepeat" is set to "0", more than "4", or is commented out, this is a finding.

Fix

Configure OL 9 to require the change of the number of repeating characters of the same character class when passwords are changed by setting the "maxclassrepeat" option.

Add the following line to "/etc/security/pwquality.conf" conf (or modify the line to have the required value):

maxclassrepeat = 4

Identifiers

Group ID
V-271618
Group title
SRG-OS-000072-GPOS-00040
Rule ID
SV-271618r1091566_rule
Check ID
C-75668r1091564_chk
Fix ID
F-75575r1091565_fix