Rule 3.3.4: if ufw is used, then the rule is overwritten

[CFoltin]

See

UBUNTU20-CIS/tasks/section_3/cis_3.3.x.yml

Line 104 in a1f61e2

- name: "AUTOMATED | 3.3.4 | PATCH | Ensure suspicious packets are logged"

Use the additional rule (maybe an additional when for ufw check is missing...)

- name: "AUTOMATED | 3.3.4 | PATCH | Ensure suspicious packets are logged, ufw part"
  sysctl:
    name: "{{ item }}"
    value: '1'
    sysctl_set: yes
    state: present
    reload: yes
    ignoreerrors: yes
    sysctl_file: /etc/ufw/sysctl.conf
  with_items:
    - net.ipv4.conf.all.log_martians
    - net.ipv4.conf.default.log_martians
  notify: sysctl flush ipv4 route table
  when:
    - ubtu20cis_rule_3_3_4
  tags:
    - level1-server
    - level1-workstation
    - automated
    - patch
    - rule_3.3.4
    - suspicious_packets
    - sysctl

[uk-bolly]

hi @CFoltin

Thank you for raising this issue. Feedback like this helps us to improve the content we supply.
I have been working through the possibilities in this request.

I believe if you have set IPT_SYSCTL= /etc/sysctl.conf
This request would not be valid and not be required

If you are using UFW and not changed the sysctl import file, still want it logged you need to add that line to the /etc/ufw/sysctl.conf as you have mentioned.

Reading into this it could be quite a bespoke setting and not actually directly listed as part of a requirement for CIS unless the options above and ufw import file not changed and the settings in the ufw file override and turn it off.

I believe what would be required is.
either

If the file /etc/ufw/sysctl.conf exists and contains *log_martians=0 then change that as well even if not using ufw?
This would also count for any other controls not just 3.3.4.

or

Do we then change the /etc/default/ufw to be IPT_SYSCTL=/etc/sysctl.conf and add a comment?
This means settings that are added into that file then are not used we not addressed in CIS?

Any thoughts?

thanks

uk-bolly

[uk-bolly]

hi @CFoltin

Thank you again for raising this issue. This has now been merged into the devel branch. Aiming to put this into main if all is well in the next couple of weeks.

many thanks again

uk-bolly

[MrSteve81]

This was added to PR #74 that addressed a lot of fixes. This has been merged to main. Thanks @CFoltin for the find.