---
title: Disable ATM Support
description: Datadog, the leading service for cloud-scale monitoring.
breadcrumbs: Docs > Datadog Security > OOTB Rules > Disable ATM Support
---

# Disable ATM Support
 
## Description{% #description %}

The Asynchronous Transfer Mode (ATM) is a protocol operating on network, data link, and physical layers, based on virtual circuits and virtual paths. To configure the system to prevent the `atm` kernel module from being loaded, add the following line to the file `/etc/modprobe.d/atm.conf`:

```
install atm /bin/false
```

This entry will cause a non-zero return value during a `atm` module installation and additionally convey the meaning of the entry to the user in form of an error message. If you would like to omit a non-zero return value and an error message, you may want to add a different line instead (both `/bin/true` and `/bin/false` are allowed by OVAL and will be accepted by the scan):

```
install atm /bin/true
```

## Rationale{% #rationale %}

Disabling ATM protects the system against exploitation of any flaws in its implementation.

## Remediation{% #remediation %}

### Shell script{% #shell-script %}

The following script can be run on the host to remediate the issue.

```bash
#!/bin/bash

# Remediation is applicable only in certain platforms
if rpm --quiet -q kernel-core; then

if LC_ALL=C grep -q -m 1 "^install atm" /etc/modprobe.d/atm.conf ; then
	
	sed -i 's#^install atm.*#install atm /bin/false#g' /etc/modprobe.d/atm.conf
else
	echo -e "\n# Disable per security requirements" >> /etc/modprobe.d/atm.conf
	echo "install atm /bin/false" >> /etc/modprobe.d/atm.conf
fi

if ! LC_ALL=C grep -q -m 1 "^blacklist atm$" /etc/modprobe.d/atm.conf ; then
	echo "blacklist atm" >> /etc/modprobe.d/atm.conf
fi

else
    >&2 echo 'Remediation is not applicable, nothing was done'
fi
```

### Ansible playbook{% #ansible-playbook %}

The following playbook can be run with Ansible to remediate the issue.

```go
- name: Gather the package facts
  package_facts:
    manager: auto
  tags:
  - CCE-89906-2
  - NIST-800-53-AC-18
  - disable_strategy
  - kernel_module_atm_disabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required

- name: Ensure kernel module 'atm' is disabled
  ansible.builtin.lineinfile:
    create: true
    dest: /etc/modprobe.d/atm.conf
    regexp: install\s+atm
    line: install atm /bin/false
  when: '"kernel-core" in ansible_facts.packages'
  tags:
  - CCE-89906-2
  - NIST-800-53-AC-18
  - disable_strategy
  - kernel_module_atm_disabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required

- name: Ensure kernel module 'atm' is blacklisted
  ansible.builtin.lineinfile:
    create: true
    dest: /etc/modprobe.d/atm.conf
    regexp: ^blacklist atm$
    line: blacklist atm
  when: '"kernel-core" in ansible_facts.packages'
  tags:
  - CCE-89906-2
  - NIST-800-53-AC-18
  - disable_strategy
  - kernel_module_atm_disabled
  - low_complexity
  - medium_disruption
  - medium_severity
  - reboot_required
```