Ensure changes to system administration scope (sudoers) is collected

LowLevel 2Automatedlinux

Description

Monitor scope changes for system administrators. If the system has been properly configured to force system administrators to log in as themselves first and then use the sudo command to execute privileged commands, it is possible to monitor changes in scope. The file /etc/sudoers, or files in /etc/sudoers.d, will be written to when the file(s) or related attributes have changed. The audit records will be tagged with the identifier "scope".

How it is checked

Audit method: Shell command

shell

alt0() { o=$(bash -c 'awk '"'"'/^ *-w/ &&/\/etc\/sudoers/ &&/ +-p *wa/ &&(/ key= *[!-~]* *$/||/ -k *[!-~]* *$/)'"'"' /etc/audit/rules.d/*.rules' 2>&1); printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- '-w /etc/sudoers -p wa -k scope' || { echo step1: missing '-w /etc/sudoers -p wa -k scope'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- '-w /etc/sudoers.d -p wa -k scope' || { echo step1: missing '-w /etc/sudoers.d -p wa -k scope'; return 1; }; o=$(bash -c 'auditctl -l | awk '"'"'/^ *-w/ &&/\/etc\/sudoers/ &&/ +-p *wa/ &&(/ key= *[!-~]* *$/||/ -k *[!-~]* *$/)'"'"'' 2>&1); printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- '-w /etc/sudoers -p wa -k scope' || { echo step2: missing '-w /etc/sudoers -p wa -k scope'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- '-w /etc/sudoers.d -p wa -k scope' || { echo step2: missing '-w /etc/sudoers.d -p wa -k scope'; return 1; }; }; if alt0; then echo compliant; fi

Expected output: compliant

How it is fixed

Fix method: Guidance or infrastructure patch

Edit or create a file in the /etc/audit/rules.d/ directory, ending in .rules extension, with the relevant rules to monitor scope changes for system administrators. Example: # printf '%s\n' "-w /etc/sudoers -p wa -k scope" "-w /etc/sudoers.d -p wa -k scope" >> /etc/audit/rules.d/50-scope.rules Merge and load the rules into active configuration: # augenrules --load Check if reboot is required. # if [[ $(auditctl -s | grep "enabled") =~ "2" ]]; then printf "Reboot required to load rules\n"; fi

Properties

Operating systems: rocky-8
Tags: cis-convertedlinux
Reference: CIS Rocky Linux 8 Benchmark v3.0.0 - 6.3.3.1

Check this host

Run this on a machine you are allowed to audit. The scan is read-only.

shell

tmaegis scan --target linux --level 2