SV-234918r958412: The SUSE operating system must generate audit records for all uses of the setxattr, fsetxattr, lsetxattr, removexattr, fremovexattr, and lremovexattr system calls. | SUSE Linux Enterprise Server 15 STIG SCAP Benchmark

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Assessment Title

Rule Text

The SUSE operating system must generate audit records for all uses of the setxattr, fsetxattr, lsetxattr, removexattr, fremovexattr, and lremovexattr 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). The system call rules are loaded into a matching engine that intercepts each syscall made by all programs on the system. Therefore, it is very important to use syscall 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 syscalls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000062-GPOS-00031, SRG-OS-000064-GPOS-00033, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000471-GPOS-00215

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

IA Controls

NIST SP 800-53

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

References

DPMS Target SUSE Linux Enterprise Server 15 DISA DPMS Target SUSE Linux Enterprise Server 15 5274

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.sles15:def:163
# The SUSE operating system must generate audit records for all uses of the setxattr, fsetxattr, lsetxattr, removexattr, fremovexattr, and lremovexattr system calls.
# Per-module read mechanism curated from static teardown of DISA's SCC tool
# (SCAP Compliance Checker) -- see the SCC Automation Reference above.

# Audit 32-bit invocations of removexattr syscall
# textfilecontent54_object (textfilecontent54_test)
test_1() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b32\s+(.*(-S\s+removexattr\s+|(\s+|,)removexattr(\s+|,))).*-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# Audit 64-bit invocations of removexattr syscall
# textfilecontent54_object (textfilecontent54_test)
test_2() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b64\s+(.*(-S\s+removexattr\s+|(\s+|,)removexattr(\s+|,))).*-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# Audit 32-bit invocations of lremovexattr syscall
# textfilecontent54_object (textfilecontent54_test)
test_3() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b32\s+(?:.*(-S\s+lremovexattr\s+|(\s+|,)lremovexattr(\s+|,))).*-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# Audit 64-bit invocations of lremovexattr syscall
# textfilecontent54_object (textfilecontent54_test)
test_4() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b64\s+(?:.*(-S\s+lremovexattr\s+|(\s+|,)lremovexattr(\s+|,))).*-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# Audit 32-bit invocations of fremovexattr syscall
# textfilecontent54_object (textfilecontent54_test)
test_5() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b32\s+(.*(-S\s+fremovexattr\s+|(\s+|,)fremovexattr(\s+|,))).*-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# Audit 64-bit invocations of fremovexattr syscall
# textfilecontent54_object (textfilecontent54_test)
test_6() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b64\s+(.*(-S\s+fremovexattr\s+|(\s+|,)fremovexattr(\s+|,))).*-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# Audit 32-bit invocations of setxattr syscall
# textfilecontent54_object (textfilecontent54_test)
test_7() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b32\s+(.*(-S\s+setxattr\s+|(\s+|,)setxattr(\s+|,))).*-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# Audit 64-bit invocations of setxattr syscall
# textfilecontent54_object (textfilecontent54_test)
test_8() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b64\s+(.*(-S\s+setxattr\s+|(\s+|,)setxattr(\s+|,))).*-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# Audit 32-bit invocations of fsetxattr syscall
# textfilecontent54_object (textfilecontent54_test)
test_9() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b32\s+(.*(-S\s+fsetxattr\s+|(\s+|,)fsetxattr(\s+|,))).*-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# Audit 64-bit invocations of fsetxattr syscall
# textfilecontent54_object (textfilecontent54_test)
test_10() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b64\s+(.*(-S\s+fsetxattr\s+|(\s+|,)fsetxattr(\s+|,))).*-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# Audit 32-bit invocations of lsetxattr syscall
# textfilecontent54_object (textfilecontent54_test)
test_11() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b32\s+(.*(-S\s+lsetxattr\s+|(\s+|,)lsetxattr(\s+|,))).*-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/etc/audit/audit.rules' &>/dev/null
}
# Audit 64-bit invocations of lsetxattr syscall
# textfilecontent54_object (textfilecontent54_test)
test_12() {
  grep -Pq '^\s*-a\s+(always,exit|exit,always)\s+-F\s+arch=b64\s+(.*(-S\s+lsetxattr\s+|(\s+|,)lsetxattr(\s+|,))).*-F\s+auid>=1000\s+-F\s+auid!=(4294967295|-1|unset)(\s+(-k\s+|-F\s+key=)[-\w]+)*\s*$' '/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 ); 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.sles15:def:163

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=b32\\s+(.*(-S\\s+setxattr\\s+|(\\s+|,)setxattr(\\s+|,))).*-F\\s+auid>=1000\\s+-F\\s+auid != (4294967295|-1|unset)(\\s+(-k\\s+|-F\\s+key=)[-\\w]+)*\\s*$" "/etc/audit/audit.rules" && \
grep -q "^\\s*-a\\s+(always,exit|exit,always)\\s+-F\\s+arch=b64\\s+(.*(-S\\s+setxattr\\s+|(\\s+|,)setxattr(\\s+|,))).*-F\\s+auid>=1000\\s+-F\\s+auid != (4294967295|-1|unset)(\\s+(-k\\s+|-F\\s+key=)[-\\w]+)*\\s*$" "/etc/audit/audit.rules" && \
grep -q "^\\s*-a\\s+(always,exit|exit,always)\\s+-F\\s+arch=b32\\s+(.*(-S\\s+removexattr\\s+|(\\s+|,)removexattr(\\s+|,))).*-F\\s+auid>=1000\\s+-F\\s+auid != (4294967295|-1|unset)(\\s+(-k\\s+|-F\\s+key=)[-\\w]+)*\\s*$" "/etc/audit/audit.rules" && \
grep -q "^\\s*-a\\s+(always,exit|exit,always)\\s+-F\\s+arch=b64\\s+(.*(-S\\s+removexattr\\s+|(\\s+|,)removexattr(\\s+|,))).*-F\\s+auid>=1000\\s+-F\\s+auid != (4294967295|-1|unset)(\\s+(-k\\s+|-F\\s+key=)[-\\w]+)*\\s*$" "/etc/audit/audit.rules" && \
grep -q "^\\s*-a\\s+(always,exit|exit,always)\\s+-F\\s+arch=b32\\s+(.*(-S\\s+lremovexattr\\s+|(\\s+|,)lremovexattr(\\s+|,))).*-F\\s+auid>=1000\\s+-F\\s+auid != (4294967295|-1|unset)(\\s+(-k\\s+|-F\\s+key=)[-\\w]+)*\\s*$" "/etc/audit/audit.rules" && \
grep -q "^\\s*-a\\s+(always,exit|exit,always)\\s+-F\\s+arch=b64\\s+(.*(-S\\s+lremovexattr\\s+|(\\s+|,)lremovexattr(\\s+|,))).*-F\\s+auid>=1000\\s+-F\\s+auid != (4294967295|-1|unset)(\\s+(-k\\s+|-F\\s+key=)[-\\w]+)*\\s*$" "/etc/audit/audit.rules" && \
grep -q "^\\s*-a\\s+(always,exit|exit,always)\\s+-F\\s+arch=b32\\s+(.*(-S\\s+fremovexattr\\s+|(\\s+|,)fremovexattr(\\s+|,))).*-F\\s+auid>=1000\\s+-F\\s+auid != (4294967295|-1|unset)(\\s+(-k\\s+|-F\\s+key=)[-\\w]+)*\\s*$" "/etc/audit/audit.rules" && \
grep -q "^\\s*-a\\s+(always,exit|exit,always)\\s+-F\\s+arch=b64\\s+(.*(-S\\s+fremovexattr\\s+|(\\s+|,)fremovexattr(\\s+|,))).*-F\\s+auid>=1000\\s+-F\\s+auid != (4294967295|-1|unset)(\\s+(-k\\s+|-F\\s+key=)[-\\w]+)*\\s*$" "/etc/audit/audit.rules" && echo "PASS"; exit 0 || echo "FAIL"; exit 1

Remediation

Configure the SUSE operating system to generate an audit record for all uses of the "setxattr", "fsetxattr", "lsetxattr","removexattr", "fremovexattr", and "lremovexattr" system calls. 

Add or update the following rules to "/etc/audit/rules.d/audit.rules":

-a always,exit -F arch=b32 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid>=1000 -F auid!=4294967295 -k perm_mod
-a always,exit -F arch=b64 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid>=1000 -F auid!=4294967295 -k perm_mod

To reload the rules file, restart the audit daemon:

> sudo systemctl restart auditd.service

or issue the following command:

> sudo augenrules --load