SV-274090r1120258: Amazon Linux 2023 must audit all uses of the truncate, ftruncate, creat, open, openat, and open_by_handle_at system calls. | Amazon Linux 2023 STIG SCAP Benchmark

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Assessment Title

Rule Text

Amazon Linux 2023 must audit all uses of the truncate, ftruncate, creat, open, openat, and open_by_handle_at system calls.

Description

Discussion Text

Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000064-GPOS-00033, SRG-OS-000466-GPOS-00210, SRG-OS-000458-GPOS-00203

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

IA Controls

NIST SP 800-53

Not mappedCCI-000130Not mappedCCI-000135Not mappedCCI-000169Not mappedCCI-002884Not mappedCCI-000172

References

DPMS Target Amazon Linux 2023 DISA DPMS Target Amazon Linux 2023 5700

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.amzlx23os:def:274090
# Amazon Linux 2023 must audit all uses of the truncate, ftruncate, creat, open, openat, and open_by_handle_at system calls.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# textfilecontent54_object (textfilecontent54_test)
test_1() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b32\s+(?:.*(-S\s+truncate\s+|(\s+|,)truncate(\s+|,))).*-F\s+exit=-EPERM\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_2() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b64\s+(?:.*(-S\s+truncate\s+|(\s+|,)truncate(\s+|,))).*-F\s+exit=-EPERM\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_3() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b32\s+(?:.*(-S\s+truncate\s+|(\s+|,)truncate(\s+|,))).*-F\s+exit=-EACCES\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_4() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b64\s+(?:.*(-S\s+truncate\s+|(\s+|,)truncate(\s+|,))).*-F\s+exit=-EACCES\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_5() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b32\s+(?:.*(-S\s+ftruncate\s+|(\s+|,)ftruncate(\s+|,))).*-F\s+exit=-EPERM\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_6() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b64\s+(?:.*(-S\s+ftruncate\s+|(\s+|,)ftruncate(\s+|,))).*-F\s+exit=-EPERM\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_7() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b32\s+(?:.*(-S\s+ftruncate\s+|(\s+|,)ftruncate(\s+|,))).*-F\s+exit=-EACCES\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_8() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b64\s+(?:.*(-S\s+ftruncate\s+|(\s+|,)ftruncate(\s+|,))).*-F\s+exit=-EACCES\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_9() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b32\s+(?:.*(-S\s+creat\s+|(\s+|,)creat(\s+|,))).*-F\s+exit=-EPERM\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_10() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b64\s+(?:.*(-S\s+creat\s+|(\s+|,)creat(\s+|,))).*-F\s+exit=-EPERM\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_11() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b32\s+(?:.*(-S\s+creat\s+|(\s+|,)creat(\s+|,))).*-F\s+exit=-EACCES\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_12() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b64\s+(?:.*(-S\s+creat\s+|(\s+|,)creat(\s+|,))).*-F\s+exit=-EACCES\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_13() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b32\s+(?:.*(-S\s+open\s+|(\s+|,)open(\s+|,))).*-F\s+exit=-EPERM\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_14() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b64\s+(?:.*(-S\s+open\s+|(\s+|,)open(\s+|,))).*-F\s+exit=-EPERM\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_15() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b32\s+(?:.*(-S\s+open\s+|(\s+|,)open(\s+|,))).*-F\s+exit=-EACCES\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_16() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b64\s+(?:.*(-S\s+open\s+|(\s+|,)open(\s+|,))).*-F\s+exit=-EACCES\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_17() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b32\s+(?:.*(-S\s+openat\s+|(\s+|,)openat(\s+|,))).*-F\s+exit=-EPERM\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_18() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b64\s+(?:.*(-S\s+openat\s+|(\s+|,)openat(\s+|,))).*-F\s+exit=-EPERM\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_19() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b32\s+(?:.*(-S\s+openat\s+|(\s+|,)openat(\s+|,))).*-F\s+exit=-EACCES\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_20() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b64\s+(?:.*(-S\s+openat\s+|(\s+|,)openat(\s+|,))).*-F\s+exit=-EACCES\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_21() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b32\s+(?:.*(-S\s+open_by_handle_at\s+|(\s+|,)open_by_handle_at(\s+|,))).*-F\s+exit=-EPERM\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_22() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b64\s+(?:.*(-S\s+open_by_handle_at\s+|(\s+|,)open_by_handle_at(\s+|,))).*-F\s+exit=-EPERM\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_23() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b32\s+(?:.*(-S\s+open_by_handle_at\s+|(\s+|,)open_by_handle_at(\s+|,))).*-F\s+exit=-EACCES\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# textfilecontent54_object (textfilecontent54_test)
test_24() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b64\s+(?:.*(-S\s+open_by_handle_at\s+|(\s+|,)open_by_handle_at(\s+|,))).*-F\s+exit=-EACCES\s+-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}

if ( test_1 && test_2 && test_3 && test_4 && test_5 && test_6 && test_7 && test_8 && test_9 && test_10 && test_11 && test_12 && test_13 && test_14 && test_15 && test_16 && test_17 && test_18 && test_19 && test_20 && test_21 && test_22 && test_23 && test_24 ); 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.amzlx23os:def:274090
if [ ! -f "/etc/audit/audit.rules" ]; then echo "PASS"; exit 0; fi
grep -q "^\\s*-a\\s+(always,exit|exit,always)\\s+-F\\s+arch=b64\\s+(?:.*(-S\\s+truncate\\s+|(\\s+|,)truncate(\\s+|,))).*-F\\s+exit=-EPERM\\s+-F\\s+auid>=1000\\s+-F\\s+auid != unset\\s*" "/etc/audit/audit.rules" && grep -q "^\\s*-a\\s+(always,exit|exit,always)\\s+-F\\s+arch=b64\\s+(?:.*(-S\\s+truncate\\s+|(\\s+|,)truncate(\\s+|,))).*-F\\s+exit=-EACCES\\s+-F\\s+auid>=1000\\s+-F\\s+auid != unset\\s*" "/etc/audit/audit.rules" && grep -q "^\\s*-a\\s+(always,exit|exit,always)\\s+-F\\s+arch=b64\\s+(?:.*(-S\\s+ftruncate\\s+|(\\s+|,)ftruncate(\\s+|,))).*-F\\s+exit=-EPERM\\s+-F\\s+auid>=1000\\s+-F\\s+auid != unset\\s*" "/etc/audit/audit.rules" && grep -q "^\\s*-a\\s+(always,exit|exit,always)\\s+-F\\s+arch=b64\\s+(?:.*(-S\\s+ftruncate\\s+|(\\s+|,)ftruncate(\\s+|,))).*-F\\s+exit=-EACCES\\s+-F\\s+auid>=1000\\s+-F\\s+auid != unset\\s*" "/etc/audit/audit.rules" || echo "FAIL"; exit 1

Remediation

Configure Amazon Linux 2023 to generate an audit event for any successful/unsuccessful use of the "truncate", "ftruncate", "creat", "open", "openat", and "open_by_handle_at" system calls by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file:

-a always,exit -F arch=b64 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access

-a always,exit -F arch=b64 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access

To load the rules to the kernel immediately, use the following command: 

$ sudo augenrules --load