SV-252947r958398: TOSS must limit the number of concurrent sessions to 256 for all accounts and/or account types. | Tri-Lab Operating System Stack (TOSS) 4 STIG SCAP Benchmark

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Assessment Title

Rule Text

TOSS must limit the number of concurrent sessions to 256 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. TOSS as an HPC operating system, is capable of supporting a large number of sessions, as well as tools which presume a larger number of concurrent sessions will be allowed. 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 should be defined based upon 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 TOSS 4 DISA DPMS Target TOSS 4 5469

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.toss4os:def:252947
# TOSS must limit the number of concurrent sessions to 256 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 256 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 256 ] ) || ( [ "$(grep -rhP --include='*.conf' '^\s*\*\s+(?:(?:hard)|(?:-))\s+maxlogins\s+(\d+)\s*$' '/etc/security/limits.d' | sed -En 's/^\s*\*\s+(?:(?:hard)|(?:-))\s+maxlogins\s+(\d+)\s*$/\1/p')" -le 256 ] )
}
# limits.conf and limits.d/*.conf:maxlogins is set to 256 or less for non-default domains
# textfilecontent54_object (textfilecontent54_test)
test_2() {
  ( [ "$(sed -En 's/^\s*[^#*\s]+\s+(?:(?:hard)|(?:-))\s+maxlogins\s+(\d+)\s*$/\1/p' '/etc/security/limits.conf')" -le 256 ] ) || ( [ "$(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 256 ] )
}

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.toss4os:def:252947

if [ ! -f "/etc/security/limits.conf" ]; then echo "PASS"; exit 0; fi
if grep -qE "^\\s*\\*\\s+(?:(?:hard)|(?:-))\\s+maxlogins\\s+256\\s*$" /etc/security/limits.conf; then echo "PASS"; exit 0; fi
for file in /etc/security/limits.d/*.conf; do
    if [ ! -f "$file" ]; then continue; fi
    if grep -qE "^\\s*\\*\\s+(?:(?:hard)|(?:-))\\s+maxlogins\\s+256\\s*$" "$file"; then echo "PASS"; exit 0; fi
done
echo "FAIL"; exit 1

Remediation

Configure TOSS to limit the number of concurrent sessions to at most 256 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 256