Check: RHEL-07-010320
Red Hat Enterprise Linux 7 STIG:
RHEL-07-010320
(in versions v3 r14 through v3 r10)
Title
The Red Hat Enterprise Linux operating system must be configured to lock accounts for a minimum of 15 minutes after three unsuccessful logon attempts within a 15-minute timeframe. (Cat II impact)
Discussion
By limiting the number of failed logon attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account. Satisfies: SRG-OS-000329-GPOS-00128, SRG-OS-000021-GPOS-00005
Check Content
Check that the system locks an account for a minimum of 15 minutes after three unsuccessful logon attempts within a period of 15 minutes with the following command: # grep pam_faillock.so /etc/pam.d/password-auth auth required pam_faillock.so preauth silent audit deny=3 even_deny_root fail_interval=900 unlock_time=900 auth [default=die] pam_faillock.so authfail audit deny=3 even_deny_root fail_interval=900 unlock_time=900 account required pam_faillock.so If the "deny" parameter is set to "0" or a value greater than "3" on both "auth" lines with the "pam_faillock.so" module, or is missing from these lines, this is a finding. If the "even_deny_root" parameter is not set on both "auth" lines with the "pam_faillock.so" module, or is missing from these lines, this is a finding. If the "fail_interval" parameter is set to "0" or is set to a value less than "900" on both "auth" lines with the "pam_faillock.so" module, or is missing from these lines, this is a finding. If the "unlock_time" parameter is not set to "0", "never", or is set to a value less than "900" on both "auth" lines with the "pam_faillock.so" module, or is missing from these lines, this is a finding. Note: The maximum configurable value for "unlock_time" is "604800". If any line referencing the "pam_faillock.so" module is commented out, this is a finding. # grep pam_faillock.so /etc/pam.d/system-auth auth required pam_faillock.so preauth silent audit deny=3 even_deny_root fail_interval=900 unlock_time=900 auth [default=die] pam_faillock.so authfail audit deny=3 even_deny_root fail_interval=900 unlock_time=900 account required pam_faillock.so If the "deny" parameter is set to "0" or a value greater than "3" on both "auth" lines with the "pam_faillock.so" module, or is missing from these lines, this is a finding. If the "even_deny_root" parameter is not set on both "auth" lines with the "pam_faillock.so" module, or is missing from these lines, this is a finding. If the "fail_interval" parameter is set to "0" or is set to a value less than "900" on both "auth" lines with the "pam_faillock.so" module, or is missing from these lines, this is a finding. If the "unlock_time" parameter is not set to "0", "never", or is set to a value less than "900" on both "auth" lines with the "pam_faillock.so" module or is missing from these lines, this is a finding. Note: The maximum configurable value for "unlock_time" is "604800". If any line referencing the "pam_faillock.so" module is commented out, this is a finding.
Fix Text
Configure the operating system to lock an account for the maximum period when three unsuccessful logon attempts in 15 minutes are made. Add/Modify the appropriate sections of the "/etc/pam.d/system-auth" and "/etc/pam.d/password-auth" files to match the following lines: auth required pam_faillock.so preauth silent audit deny=3 even_deny_root fail_interval=900 unlock_time=900 auth sufficient pam_unix.so try_first_pass auth [default=die] pam_faillock.so authfail audit deny=3 even_deny_root fail_interval=900 unlock_time=900 account required pam_faillock.so Note: Per requirement RHEL-07-010199, RHEL 7 must be configured to not overwrite custom authentication configuration settings while using the authconfig utility, otherwise manual changes to the listed files will be overwritten whenever the authconfig utility is used.
Additional Identifiers
Rule ID: SV-204427r880842_rule
Vulnerability ID: V-204427
Group Title: SRG-OS-000329-GPOS-00128
Expert Comments
CCIs
| Number | Definition |
|---|---|
| CCI-000044 |
The information system enforces the organization-defined limit of consecutive invalid logon attempts by a user during the organization-defined time period. |
| CCI-002236 |
The organization defines the time period the information system will automatically lock the account or node when the maximum number of unsuccessful logon attempts is exceeded. |
| CCI-002237 |
The organization defines the delay algorithm to be employed by the information system to delay the next logon prompt when the maximum number of unsuccessful logon attempts is exceeded. |
| CCI-002238 |
The information system automatically locks the account or node for either an organization-defined time period, until the locked account or node is released by an administrator, or delays the next logon prompt according to the organization-defined delay algorithm when the maximum number of unsuccessful logon attempts is exceeded. |
Controls
| Number | Title |
|---|---|
| AC-7 |
Unsuccessful Logon Attempts |