TMAegis
More rules for linux

TMA-ROCKY8-6.2.3.1

Ensure access to all logfiles has been configured

MediumLevel 1Automatedlinux

Description

Log files contain information from many services on the the local system, or in the event of a centralized log server, others systems logs as well. In general log files are found in /var/log/, although application can be configured to store logs elsewhere. Should your application store logs in another, ensure to run the same test on that location.

How it is checked

Audit method: Shell command

shell
alt0() { o=$(bash -c '#!/usr/bin/env bash

{
   a_output=(); a_output2=()
   f_file_test_chk()
   {
      a_out2=()
      maxperm="$( printf '"'"'%o'"'"' $(( 0777 & ~$perm_mask)) )"
      [ $(( $l_mode & $perm_mask )) -gt 0 ] && \
         a_out2+=("   o Mode: \"$l_mode\" should be \"$maxperm\" or more restrictive")
      [[ ! "$l_user" =~ $l_auser ]] && \
         a_out2+=("   o Owned by: \"$l_user\" and should be owned by \"${l_auser//|/ or }\"")
      [[ ! "$l_group" =~ $l_agroup ]] && \
         a_out2+=("   o Group owned by: \"$l_group\" and should be group owned by \"${l_agroup//|/ or }\"")
      [ "${#a_out2[@]}" -gt 0 ] && a_output2+=(" - File: \"$l_fname\" is:" "${a_out2[@]}")
   }
   while IFS= read -r -d $'"'"'\0'"'"' l_file; do
      while IFS=: read -r l_fname l_mode l_user l_group; do
         if grep -Pq -- '"'"'\/(apt)\h*$'"'"' <<< "$(dirname "$l_fname")"; then
            perm_mask='"'"'0133'"'"' l_auser="root" l_agroup="(root|adm)"; f_file_test_chk
         else
            case "$(basename "$l_fname")" in
               lastlog | lastlog.* | wtmp | wtmp.* | wtmp-* | btmp | btmp.* | btmp-* | README)
                  perm_mask='"'"'0113'"'"' l_auser="root" l_agroup="(root|utmp)"
                  f_file_test_chk ;;
               cloud-init.log* | localmessages* | waagent.log*)
                  perm_mask='"'"'0133'"'"' l_auser="(root|syslog)" l_agroup="(root|adm)"
                  file_test_chk ;;
               secure{,*.*,.*,-*} | auth.log | syslog | messages)
                  perm_mask='"'"'0137'"'"' l_auser="(root|syslog)" l_agroup="(root|adm)"
                  f_file_test_chk ;;
               SSSD | sssd)
                  perm_mask='"'"'0117'"'"' l_auser="(root|SSSD)" l_agroup="(root|SSSD)"
                  f_file_test_chk ;;
               gdm | gdm3)
                  perm_mask='"'"'0117'"'"' l_auser="root" l_agroup="(root|gdm|gdm3)"
                  f_file_test_chk ;;
               *.journal | *.journal~)
                  perm_mask='"'"'0137'"'"' l_auser="root" l_agroup="(root|systemd-journal)"
                  f_file_test_chk ;;
               *)
                  perm_mask='"'"'0137'"'"' l_auser="(root|syslog)" l_agroup="(root|adm)"
                  if [ "$l_user" = "root" ] || ! grep -Pq -- "^\h*$(awk -F: '"'"'$1=="'"'"'"$l_user"'"'"'" {print $7}'"'"' /etc/passwd)\b" /etc/shells; then
                     ! grep -Pq -- "$l_auser" <<< "$l_user" && l_auser="(root|syslog|$l_user)"
                     ! grep -Pq -- "$l_agroup" <<< "$l_group" && l_agroup="(root|adm|$l_group)"
                  fi
                  f_file_test_chk ;;
            esac
         fi
      done < <(stat -Lc '"'"'%n:%#a:%U:%G'"'"' "$l_file")
   done < <(find -L /var/log -type f \( -perm /0137 -o ! -user root -o ! -group root \) -print0)
   if [ "${#a_output2[@]}" -le 0 ]; then
      a_output+=("  - All files in \"/var/log/\" have appropriate permissions and ownership")
      printf '"'"'\n%s'"'"' "- Audit Result:" "  ** PASS **" "${a_output[@]}" ""
   else
      printf '"'"'\n%s'"'"' "- Audit Result:" "  ** FAIL **" " - Reason(s) for audit failure:" "${a_output2[@]}" ""
   fi
}' 2>&1); printf '%s\n' "$o" | grep -q '\*\* PASS \*\*' || { echo "step1: script did not report PASS"; return 1; }; }; if alt0; then echo compliant; fi
Expected output
compliant

How it is fixed

Fix method: Guidance or infrastructure patch

Run the following script to update permissions and ownership on files in /var/log. Although the script is not destructive, ensure that the output is captured in the event that the remediation causes issues. #!/usr/bin/env bash { a_output2=() f_file_test_fix() { a_out2=() maxperm="$( printf '%o' $(( 0777 & ~$perm_mask)) )" if [ $(( $l_mode & $perm_mask )) -gt 0 ]; then a_out2+=(" o Mode: \"$l_mode\" should be \"$maxperm\" or more restrictive" " x Removing excess permissions") chmod "$l_rperms" "$l_fname" fi if [[ ! "$l_user" =~ $l_auser ]]; then a_out2+=(" o Owned by: \"$l_user\" and should be owned by \"${l_auser//|/ or }\"" " x Changing ownership to: \"$l_fix_account\"") chown "$l_fix_accou…

Properties

Operating systems
rocky-8
Tags
cis-convertedlinux
Reference
CIS Rocky Linux 8 Benchmark v3.0.0 - 6.2.3.1

Check this host

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

shell
tmaegis scan --target linux