Vulnerability Discussion

If the permissions of cron configuration files or directories are modified from the operating system defaults, it may be possible for individuals to insert unauthorized cron jobs that perform unauthorized actions, including potentially escalating privileges.

Check

Run the following command to verify that the owner, group, and mode of cron configuration files and directories match the operating system defaults:

$ rpm --verify cronie crontabs | awk '! ($2 == "c" && $1 ~ /^.\..\.\.\.\..\./) {print $0}'

If the command returns any output, this is a finding.

If there are findings, run the following command to determine what the permissions are:

$ ls -ld /etc/cron*
drwxr-xr-x. 2 root root 21 Oct 3 2024 /etc/cron.d
drwxr-xr-x. 2 root root 6 May 1 09:03 /etc/cron.daily
-rw-r--r--. 1 root root 0 Oct 3 2024 /etc/cron.deny
drwxr-xr-x. 2 root root 22 Mar 5 12:49 /etc/cron.hourly
drwxr-xr-x. 2 root root 6 Mar 23 2022 /etc/cron.monthly
-rw-r--r--. 1 root root 451 Mar 23 2022 /etc/crontab
drwxr-xr-x. 2 root root 6 Mar 23 2022 /etc/cron.weekly

Fix

Run the following commands to restore the permissions of cron configuration files and directories to the operating system defaults:

$ sudo dnf reinstall cronie crontabs
$ rpm --setugids cronie crontabs
$ rpm --setperms cronie crontabs