SV-258069r958398: RHEL 9 must limit the number of concurrent sessions to ten for all accounts and/or account types. | Red Hat Enterprise Linux 9 STIG SCAP Benchmark

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Assessment Title

Rule Text

RHEL 9 must limit the number of concurrent sessions to ten for all accounts and/or account types.

Description

Discussion Text

Operating system management includes the ability to control the number of users and user sessions that utilize an operating system. Limiting the number of allowed users and sessions per user is helpful in reducing the risks related to denial-of-service (DoS) attacks. This requirement addresses concurrent sessions for information system accounts and does not address concurrent sessions by single users via multiple system accounts. The maximum number of concurrent sessions must be defined based on mission needs and the operational environment for each system.

How this relates to the STIG checklist: STIG vs SCAP benchmark.

IA Controls

NIST SP 800-53

Not mappedCCI-000054

References

DPMS Target Red Hat Enterprise Linux 9 DISA DPMS Target Red Hat Enterprise Linux 9 5551

SCC Automation Reference

The reconstructed evaluation script behind this rule's OVAL check(s) — every module a compound check combines, with this rule's own concrete values and DISA's SCC tool's real per-module mechanism curated from static teardown of SCC releases.

#!/bin/bash
# Reconstructed from oval:mil.disa.stig.rhel9os:def:258069
# RHEL 9 must limit the number of concurrent sessions to ten for all accounts and/or account types.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# limits.conf and limits.d/*.conf:maxlogins is set to 10 or less by default
# textfilecontent54_object (textfilecontent54_test)
test_1() {
  ( [ "$(sed -En 's/^\s*\*\s+(?:(?:hard)|(?:-))\s+maxlogins\s+(\d+)\s*$/\1/p' '/etc/security/limits.conf')" -le 10 ] ) || ( [ "$(grep -rhP --include='*.conf' '^\s*\*\s+(?:(?:hard)|(?:-))\s+maxlogins\s+(\d+)\s*$' '/etc/security/limits.d' | sed -En 's/^\s*\*\s+(?:(?:hard)|(?:-))\s+maxlogins\s+(\d+)\s*$/\1/p')" -le 10 ] )
}
# limits.conf and limits.d/*.conf:maxlogins is set to 10 or less for non-default domains
# textfilecontent54_object (textfilecontent54_test)
test_2() {
  ( [ "$(sed -En 's/^\s*[^#*\s]+\s+(?:(?:hard)|(?:-))\s+maxlogins\s+(\d+)\s*$/\1/p' '/etc/security/limits.conf')" -le 10 ] ) || ( [ "$(grep -rhP --include='*.conf' '^\s*[^#*\s]+\s+(?:(?:hard)|(?:-))\s+maxlogins\s+(\d+)\s*$' '/etc/security/limits.d' | sed -En 's/^\s*[^#*\s]+\s+(?:(?:hard)|(?:-))\s+maxlogins\s+(\d+)\s*$/\1/p')" -le 10 ] )
}

if ( test_1 && test_2 ); then
  echo "PASS"
else
  echo "FAIL"
fi

Assessment Script Powered by AISandbox-executed

A standalone Shell script to assess this control automatically. Review before running it in your environment.

Syntax-checked and actually executed in an isolated sandbox (not the real system this checks) — confirmed to run without errors.

#!/bin/sh
# OVAL Definition: oval:mil.disa.stig.rhel9os:def:258069

if [ ! -f "/etc/security/limits.conf" ] || [ ! $(grep -q "^\\s*\\*\\s+hard\\s+maxlogins\\s+10\\s*$" /etc/security/limits.conf || true) ]; then
  for file in /etc/security/limits.d/*.conf; do
    if [ -f "$file" ] && [ $(grep -q "^\\s*\\*\\s+hard\\s+maxlogins\\s+10\\s*$" "$file" || true) ]; then
      break
    fi
  done
  if [ ! -e "$file" ]; then
    echo "FAIL"
    exit 1
  fi
fi
echo "PASS"
exit 0

Remediation

Configure RHEL 9 to limit the number of concurrent sessions to "10" for all accounts and/or account types.

Add the following line to the top of the /etc/security/limits.conf or in a ".conf" file defined in /etc/security/limits.d/:

* hard maxlogins 10