Securing Veeam Hardened Repository

After selecting the right hardware for the Veeam Backup & Replication Hardened Repository and installing the Ubuntu Linux operating system, the next step is secure the operating system according to the DISA STIG (Defense Information Systems Agency Security Technical Implementation Guides) guidelines.

This blog post describes the hardening process for Ubuntu 20.04 free edition. For Ubuntu Pro users, there is an easier way. To keep it as simple as possible, Veeam provides a script that automates the setting of security options. The requirement for the script to work is such that Ubuntu is set up as described in the installing the Ubuntu Linux blog post.

Prerequisites

Before starting the hardening process, let’s recap the current state and adjust settings if needed.

That’s it! Let’s start securing Veeam Hardened Repository.

Getting started

After installing Ubuntu as described in this blog post, there are two ways to connect or manage the Veeam Hardened Repository.

  1. Direct login via the console (usually via a remote management console web interface)
  2. SSH (secure shell)

The easiest way is using SSH, because it supports copy and paste. One popular SSH client is Putty, which is included in the Veeam Backup & Replication installation.

Log in to the Hardened Repository server with your credentials (SSH or console). Then download the script with:

wget https://vee.am/harddisa

Before running the script, it’s recommended that you understand what it does and what it does not do. The script applies DISA STIG security settings where applicable. That means the script implements things like password policies, audit rules, permissions or TCP security settings. The STIGs also have requirements for systems with graphical user interface or user management via a directory service. As the Hardened Repository is a “minimal installation” standalone machine, things like that don’t apply and are “not applicable”. A full list of settings is available in the Appendix.

This guide assumes that customers reading this guide are new to Linux or have only basic Linux knowledge. The hardening script skips settings that have notifications where someone should do something manually on the Hardened Repository server as root. That is because the final and manual hardening step after the Veeam hardening script will remove root and sudo permissions and disable SSH remote management. This is a hard step, but it addresses concerns around “I can log in as root and delete files.”

Note:
Only Veeam Backup & Replication v12 and later is compatible with DISA STIG hardening. If you are using earlier versions, please upgrade to V12 first.

For advanced Linux users: Feel free to use the script to save time. If you are using automation with Ansible, there is material available for that as well.

Apply DISA STIG Requirements

You can also apply each hardening step of the DISA STIGs manually. On the DISA document library, search for Ubuntu, download the guidelines and open them with DISA STIG Viewer. Most rules have a code example to apply the guideline.

The script in this article handles the rules of the guidelines to make your life easier. Before running the hardening script, one needs to make sure that NTP traffic is allowed to the servers listed in the script (tick.usno.navy.mil, tock.usno.navy.mil and ntp2.usno.navy.mil). Alternatively, one can change the script to other time sources, or configure time manually and delete the time configuration section in the script. Apply the guidelines by running the script with the following command:

sudo bash harddisa

The output will look like this. Explanations on all the steps are provided later in this document.

After the hardening script finished, the Veeam Hardened Repository role can be installed.

Install Hardened Repository Role

Technically, installing the Hardened Repository role could also be done before doing the hardening. Before adding the Hardened Repository role, you need to configure the filesystem path where the backup data will be stored in future. In the “Installing Ubuntu Linux for Veeam Hardened Repository” blog, we defined /mnt/backup as the path for backup data storage. This path needs to be owned by the Hardened Repository user and we will limit permissions only to that user (veeamrepo in our case):

sudo chown –R veeamrepo:veeamrepo /mnt/backup
sudo chmod 700 /mnt/backup

The user guide describes how to install the Veeam Hardened Repository role. Please note that the ‘use “su” if “sudo” fails’ option cannot be used because the root account has no password/is locked.

After installation of the Hardened Repository, there is still one user with full “sudo” privileges. Let’s close this.

Locking It Down

There are a few steps where we decided to keep it a manual process instead of automating it with the hardening script. One of them (others are described in the appendix table) is UBTU-20-010009, which states: “Ubuntu operating systems when booted must require authentication upon booting into single-user and maintenance modes.”Single-user mode is a way to get into the system after locking down Hardened Repository as described in the next section.

Protecting single-user mode against unauthorized access is described in a separate blog post.

These following steps are outside the official DISA STIG hardening guides. These steps are the answer to customer concerns about the security of Hardened Repository and the criticism that one can “simply” log in as root and delete everything.

Note:
Only do the following steps after installing the Hardened Repository role. You will no longer have root/administrative access to the machine after executing the following steps. If you have locked yourself out accidentally, please refer to the “Ubuntu Linux essentials: Booting into single user mode and protecting against unauthorized access” blog post.

First, we will disable SSH remote management. The following command disables the SSH service, so that it does not start automatically during boot time.

sudo systemctl disable ssh

You can continue working with SSH until the next reboot. You can also stop the SSH service directly and the current SSH session will continue to work. But you can no longer reconnect after stopping the SSH service. The following command stops the SSH service:

sudo systemctl stop ssh 

The last commands above used “sudo” to give you root permissions. Root permissions are no longer needed to run Veeam Hardened Repository. We will only allow two commands: reboot and shutdown.

The overall concept of the following steps is also described in the Installing Ubuntu Linux for Veeam Hardened Repository blog post.

Replace the username with the username “veeamrepo” you are currently using:

sudo bash -c "echo 'veeamrepo ALL = (root) NOEXEC: /usr/sbin/reboot' >> /etc/sudoers"
sudo bash -c "echo 'veeamrepo ALL = (root) NOEXEC: /usr/sbin/shutdown' >> /etc/sudoers"

Now remove yourself from the sudo group. After executing the command below and next login, you lose your sudo permissions. To get full root/sudo permissions again, you must boot into “single-user mode”. Run this command only as last step!

sudo deluser veeamrepo sudo

With that, the configuration of the Hardened Repository itself is finished. But there are some more settings to become compliant with DISA STIGs.

Required Configurations on the Veeam Backup & Replication Side

There are DISA STIG requirements around encryption (see table below) that can be configured on the Hardened Repository directly or in Veeam Backup & Replication. The operating system data itself does not require protection. Only the backup data needs to be protected. One can protect the backup data also via disk encryption, but that increases complexity. It’s easier to manage encryption on the Veeam Backup & Replication side in the job settings.

STIG ID Severity Rule title Explanation
UBTU-20-010414 medium Ubuntu operating systems handling data requiring “data at rest” protections must employ cryptographic mechanisms to prevent unauthorized disclosure and modification of the information at rest. Configure health checks and encryption in the job settings.
Disk encryption could be used alternatively.
UBTU-20-010444 medium Ubuntu operating system must implement cryptographic mechanisms to prevent unauthorized modification of all information at rest. Configure health checks in the job settings.
Disk encryption could be used alternatively.
UBTU-20-010445 medium Ubuntu operating system must implement cryptographic mechanisms to prevent unauthorized disclosure of all information at rest. Configure encryption in the job settings.
Disk encryption could be used alternatively.

Summary

As a “software only” vendor, Veeam offers customers flexibility regarding which hardware or operating system to use. On the other hand, customers ask for security best practices. Note the following blog series:

  1. Selecting Hardware and Setting Up Environment for Veeam Hardened Repository
  2. Installing Ubuntu Linux for Veeam Hardened Repository
  3. Securing Veeam Hardened Repository (this blog post)

With this blog series, customers are prepared to achieve trusted immutability by applying globally recognized DISA STIG cybersecurity standards on top of Veeam best practices. If you are looking for pre-configured immutable hardware, where you don’t need to manage the hardware and operating system yourself, then there are several options:

Appendix

The table below shows DISA STIG requirements that must be applied manually on the server hardware or in Veeam Backup & Replication.

STIG ID Severity Rule title Comment
UBTU-20-010009 high Ubuntu operating systems when booted must require authentication upon booting into single-user and maintenance modes. Described above
UBTU-20-010012 high The Ubuntu operating system must ensure only users who need access to security functions are part of sudo group. Described above
UBTU-20-010414 medium Ubuntu operating systems handling data requiring “data at rest” protections must employ cryptographic mechanisms to prevent unauthorized disclosure and modification of the information at rest. Described above
UBTU-20-010444 medium Ubuntu operating system must implement cryptographic mechanisms to prevent unauthorized modification of all information at rest. Described above
UBTU-20-010445 medium Ubuntu operating system must implement cryptographic mechanisms to prevent unauthorized disclosure of all information at rest. Described above
UBTU-20-010447 medium The Ubuntu operating system must implement non-executable data to protect its memory from unauthorized code execution. BIOS/UEFI setting
UBTU-20-010455 medium The Ubuntu operating system must disable all wireless network adapters. Ensure that no wireless network adapters are used

The table below shows the DISA STIG requirements that were implemented automatically by the script or are default settings.

STIG ID Severity Rule Title Comment

UBTU-20-010005

medium

The Ubuntu operating system must allow users to directly initiate a session lock for all connection types.

 

UBTU-20-010007

low

The Ubuntu operating system must enforce 24 hours/1 day as the minimum password lifetime. Passwords for new users must have a 24 hours/1 day minimum password lifetime restriction.

 

UBTU-20-010008

low

The Ubuntu operating system must enforce a 60-day maximum password lifetime restriction. Passwords for new users must have a 60-day maximum password lifetime restriction.

 

UBTU-20-010013

medium

The Ubuntu operating system must automatically terminate a user session after inactivity timeouts have expired.

 

UBTU-20-010014

medium

The Ubuntu operating system must require users to reauthenticate for privilege escalation or when changing roles.

 

UBTU-20-010016

medium

The Ubuntu operating system default filesystem permissions must be defined in such a way that all authenticated users can read and modify only their own files.

 

UBTU-20-010035

medium

The Ubuntu operating system must use strong authenticators in establishing nonlocal maintenance and diagnostic sessions.

 

UBTU-20-010036

medium

The Ubuntu operating system must immediately terminate all network connections associated with SSH traffic after a period of inactivity.

 

UBTU-20-010037

medium

The Ubuntu operating system must immediately terminate all network connections associated with SSH traffic at the end of the session or after 10 minutes of inactivity.

 

UBTU-20-010038

medium

The Ubuntu operating system must display the Standard Mandatory DoD Notice and Consent Banner before granting any local or remote connection to the system.

Generic banner is used instead of DoD Notice.

UBTU-20-010042

high

The Ubuntu operating system must use SSH to protect the confidentiality and integrity of transmitted information.

 

UBTU-20-010043

medium

The Ubuntu operating system must configure the SSH daemon to use Message Authentication Codes (MACs) employing FIPS 140-2 approved cryptographic hashes to prevent the unauthorized disclosure of information and/or detect changes to information during transmission.

 

UBTU-20-010047

high

The Ubuntu operating system must not allow unattended or automatic login via SSH.

 

UBTU-20-010048

high

The Ubuntu operating system must be configured so that remote X connections are disabled, unless to fulfill documented and validated mission requirements.

 

UBTU-20-010049

medium

The Ubuntu operating system SSH daemon must prevent remote hosts from connecting to the proxy display.

 

UBTU-20-010050

low

The Ubuntu operating system must enforce password complexity by requiring that at least one upper-case character be used.

 

UBTU-20-010051

low

The Ubuntu operating system must enforce password complexity by requiring that at least one lower-case character be used.

 

UBTU-20-010052

low

The Ubuntu operating system must enforce password complexity by requiring that at least one numeric character be used.

 

UBTU-20-010053

low

The Ubuntu operating system must require the change of at least 8 characters when passwords are changed.

 

UBTU-20-010054

medium

The Ubuntu operating system must enforce a minimum 15-character password length.

 

UBTU-20-010055

low

The Ubuntu operating system must enforce password complexity by requiring that at least one special character be used.

 

UBTU-20-010056

medium

The Ubuntu operating system must prevent the use of dictionary words for passwords.

 

UBTU-20-010057

medium

The Ubuntu operating system must be configured so that when passwords are changed or new passwords are established, pwquality must be used.

 

UBTU-20-010070

low

The Ubuntu operating system must prohibit password reuse for a minimum of five generations.

 

UBTU-20-010072

low

The Ubuntu operating system must automatically lock an account until the locked account is released by an administrator when three unsuccessful logon attempts have been made.

 

UBTU-20-010074

medium

The Ubuntu operating system must be configured so that the script which runs each 30 days or less to check file integrity is the default one.

 

UBTU-20-010075

low

The Ubuntu operating system must enforce a delay of at least 4 seconds between logon prompts following a failed logon attempt.

 

UBTU-20-010100

medium

The Ubuntu operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/passwd.

 

UBTU-20-010101

medium

The Ubuntu operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/group.

 

UBTU-20-010102

medium

The Ubuntu operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/shadow.

 

UBTU-20-010103

medium

The Ubuntu operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/gshadow.

 

UBTU-20-010104

medium

The Ubuntu operating system must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/opasswd.

 

UBTU-20-010118

medium

The Ubuntu operating system must shut down by default upon audit failure (unless availability is an overriding concern).

 

UBTU-20-010122

medium

The Ubuntu operating system must be configured so that audit log files are not read or write-accessible by unauthorized users.

 

UBTU-20-010123

medium

The Ubuntu operating system must be configured to permit only authorized users ownership of the audit log files.

 

UBTU-20-010124

medium

The Ubuntu operating system must permit only authorized groups ownership of the audit log files.

 

UBTU-20-010128

medium

The Ubuntu operating system must be configured so that the audit log directory is not write-accessible by unauthorized users.

 

UBTU-20-010133

medium

The Ubuntu operating system must be configured so that audit configuration files are not write-accessible by unauthorized users.

 

UBTU-20-010134

medium

The Ubuntu operating system must permit only authorized accounts to own the audit configuration files.

 

UBTU-20-010135

medium

The Ubuntu operating system must permit only authorized groups to own the audit configuration files.

 

UBTU-20-010136

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the su command.

 

UBTU-20-010137

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the chfn command.

 

UBTU-20-010138

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the mount command.

 

UBTU-20-010139

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the umount command.

 

UBTU-20-010140

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the ssh-agent command.

 

UBTU-20-010141

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the ssh-keysign command.

 

UBTU-20-010142

medium

The Ubuntu operating system must generate audit records for any use of the setxattr, fsetxattr, lsetxattr, removexattr, fremovexattr, and lremovexattr system calls.

 

UBTU-20-010148

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the chown, fchown, fchownat, and lchown system calls.

 

UBTU-20-010152

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the chmod, fchmod, and fchmodat system calls.

 

UBTU-20-010155

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the creat, open, openat, open_by_handle_at, truncate, and ftruncate system calls.

 

UBTU-20-010161

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the sudo command.

 

UBTU-20-010162

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the sudoedit command.

 

UBTU-20-010163

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the chsh command.

 

UBTU-20-010164

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the newgrp command.

 

UBTU-20-010165

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the chcon command.

 

UBTU-20-010166

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the apparmor_parser command.

 

UBTU-20-010167

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the setfacl command.

 

UBTU-20-010168

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the chacl command.

 

UBTU-20-010169

medium

The Ubuntu operating system must generate audit records for the use and modification of the tallylog file.

 

UBTU-20-010170

medium

The Ubuntu operating system must generate audit records for the use and modification of faillog file.

 

UBTU-20-010171

medium

The Ubuntu operating system must generate audit records for the use and modification of the lastlog file.

 

UBTU-20-010172

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the passwd command.

 

UBTU-20-010173

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the unix_update command.

 

UBTU-20-010174

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the gpasswd command.

 

UBTU-20-010175

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the chage command.

 

UBTU-20-010176

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the usermod command.

 

UBTU-20-010177

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the crontab command.

 

UBTU-20-010178

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the pam_timestamp_check command.

 

UBTU-20-010179

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the init_module and finit_module syscalls.

 

UBTU-20-010181

medium

The Ubuntu operating system must generate audit records for successful/unsuccessful uses of the delete_module syscall.

 

UBTU-20-010182

medium

The Ubuntu operating system must produce audit records and reports containing information to establish when, where, what type, the source, and the outcome for all DoD-defined auditable events and actions in near real time.

 

UBTU-20-010198

medium

The Ubuntu operating system must initiate session audits at system start-up.

 

UBTU-20-010199

medium

The Ubuntu operating system must configure audit tools with a mode of 0755 or less permissive.

 

UBTU-20-010200

medium

The Ubuntu operating system must configure audit tools to be owned by root.

 

UBTU-20-010201

medium

The Ubuntu operating system must configure the audit tools to be group-owned by root.

 

UBTU-20-010205

medium

The Ubuntu operating system must use cryptographic mechanisms to protect the integrity of audit tools.

 

UBTU-20-010211

medium

The Ubuntu operating system must prevent all software from executing at higher privilege levels than users executing the software and the audit system must be configured to audit the execution of privileged functions.

 

UBTU-20-010230

low

The Ubuntu operating system must record time stamps for audit records that can be mapped to Coordinated Universal Time (UTC) or Greenwich Mean Time (GMT).

 

UBTU-20-010244

medium

The Ubuntu operating system must generate audit records for privileged activities, nonlocal maintenance, diagnostic sessions and other system-level access.

 

UBTU-20-010267

medium

The Ubuntu operating system must generate audit records for any successful/unsuccessful use of unlink, unlinkat, rename, renameat, and rmdir system calls.

 

UBTU-20-010277

medium

The Ubuntu operating system must generate audit records for the /var/log/wtmp file.

 

UBTU-20-010278

medium

The Ubuntu operating system must generate audit records for the /var/run/wtmp file.

 

UBTU-20-010279

medium

The Ubuntu operating system must generate audit records for the /var/log/btmp file.

 

UBTU-20-010296

medium

The Ubuntu operating system must generate audit records when successful/unsuccessful attempts to use modprobe command.

 

UBTU-20-010297

medium

The Ubuntu operating system must generate audit records when successful/unsuccessful attempts to use the kmod command.

 

UBTU-20-010298

medium

The Ubuntu operating system must generate audit records when successful/unsuccessful attempts to use the fdisk command.

 

UBTU-20-010400

low

The Ubuntu operating system must limit the number of concurrent sessions to ten for all accounts and/or account types.

 

UBTU-20-010403

medium

The Ubuntu operating system must monitor remote access methods.

 

UBTU-20-010404

medium

The Ubuntu operating system must encrypt all stored passwords with a FIPS 140-2 approved cryptographic hashing algorithm.

 

UBTU-20-010405

high

The Ubuntu operating system must not have the telnet package installed.

 

UBTU-20-010406

high

The Ubuntu operating system must not have the rsh-server package installed.

 

UBTU-20-010407

medium

The Ubuntu operating system must be configured to prohibit or restrict the use of functions, ports, protocols, and/or services, as defined in the PPSM CAL and vulnerability assessments.

 

UBTU-20-010408

medium

The Ubuntu operating system must prevent direct login into the root account.

 

UBTU-20-010411

medium

The Ubuntu operating system must set a sticky bit on all public directories to prevent unauthorized and unintended information transferred via shared system resources.

 

UBTU-20-010412

medium

The Ubuntu operating system must be configured to use TCP syncookies.

 

UBTU-20-010413

medium

The Ubuntu operating system must disable kernel core dumps so that it can fail to a secure state if system initialization fails, shutdown fails or aborts fail.

 

UBTU-20-010416

medium

The Ubuntu operating system must generate error messages that provide information necessary for corrective actions without revealing information that could be exploited by adversaries.

 

UBTU-20-010417

medium

The Ubuntu operating system must configure the /var/log directory to be group-owned by syslog.

 

UBTU-20-010418

medium

The Ubuntu operating system must configure the /var/log directory to be owned by root.

 

UBTU-20-010419

medium

The Ubuntu operating system must configure the /var/log directory to have mode 0750 or less permissive.

 

UBTU-20-010420

medium

The Ubuntu operating system must configure the /var/log/syslog file to be group-owned by adm.

Logs of processes running with reduced permissions are in /tmp/VeeamBackup because of this

UBTU-20-010421

medium

The Ubuntu operating system must configure /var/log/syslog file to be owned by syslog.

 

UBTU-20-010422

medium

The Ubuntu operating system must configure /var/log/syslog file with mode 0640 or less permissive.

 

UBTU-20-010423

medium

The Ubuntu operating system must have directories that contain system commands set to a mode of 0755 or less permissive.

 

UBTU-20-010424

medium

The Ubuntu operating system must have directories that contain system commands owned by root.

 

UBTU-20-010425

medium

The Ubuntu operating system must have directories that contain system commands group-owned by root.

 

UBTU-20-010426

medium

The Ubuntu operating system library files must have mode 0755 or less permissive.

 

UBTU-20-010427

medium

The Ubuntu operating system library directories must have mode 0755 or less permissive.

 

UBTU-20-010428

medium

The Ubuntu operating system library files must be owned by root.

 

UBTU-20-010429

medium

The Ubuntu operating system library directories must be owned by root.

 

UBTU-20-010430

medium

The Ubuntu operating system library files must be group-owned by root or a system account.

 

UBTU-20-010431

medium

The Ubuntu operating system library directories must be group-owned by root.

 

UBTU-20-010432

medium

The Ubuntu operating system must be configured to preserve log records from failure events.

 

UBTU-20-010433

medium

The Ubuntu operating system must have an application firewall installed in order to control remote access methods.

 

UBTU-20-010434

medium

The Ubuntu operating system must enable and run the uncomplicated firewall(ufw).

 

UBTU-20-010435

medium

The Ubuntu operating system must, for networked systems, compare internal information system clocks at least every 24 hours with a server which is synchronized to one of the redundant United States Naval Observatory (USNO) time servers, or a time server designated for the appropriate DoD network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS).

The script sets the “-R” flag in /etc/defaults/chrony

 

That prevents chrony from making big time changes during boot or restart of the service. See this blog post for details.

 

UBTU-20-010438

medium

The Ubuntu operating system’s Advance Package Tool (APT) must be configured to prevent the installation of patches, service packs, device drivers, or Ubuntu operating system components without verification they have been digitally signed using a certificate that is recognized and approved by the organization.

 

UBTU-20-010439

medium

The Ubuntu operating system must be configured to use AppArmor.

 

UBTU-20-010446

medium

The Ubuntu operating system must configure the uncomplicated firewall to rate-limit impacted network interfaces.

 

UBTU-20-010448

medium

The Ubuntu operating system must implement address space layout randomization to protect its memory from unauthorized code execution.

 

UBTU-20-010449

medium

The Ubuntu operating system must be configured so that Advance Package Tool (APT) removes all software components after updated versions have been installed.

 

UBTU-20-010450

medium

The Ubuntu operating system must use a file integrity tool to verify correct operation of all security functions.

 

UBTU-20-010451

medium

The Ubuntu operating system must notify designated personnel if baseline configurations are changed in an unauthorized manner. The file integrity tool must notify the System Administrator when changes to the baseline configuration or anomalies in the operation of any security functions are discovered.

 

UBTU-20-010453

low

The Ubuntu operating system must display the date and time of the last successful account logon upon logon.

 

UBTU-20-010454

medium

The Ubuntu operating system must have an application firewall enabled.

 

UBTU-20-010456

medium

The Ubuntu operating system must have system commands set to a mode of 0755 or less permissive.

 

UBTU-20-010457

medium

The Ubuntu operating system must have system commands owned by root or a system account.

 

UBTU-20-010458

medium

The Ubuntu operating system must have system commands group-owned by root or a system account.

 

UBTU-20-010460

high

The Ubuntu operating system must disable the x86 Ctrl-Alt-Delete key sequence.

 

UBTU-20-010462

high

The Ubuntu operating system must not have accounts configured with blank or null passwords.

 

UBTU-20-010463

high

The Ubuntu operating system must not allow accounts configured with blank or null passwords.

 

UBTU-20-010461

medium

The Ubuntu operating system must disable automatic mounting of Universal Serial Bus (USB) mass storage driver.

 

The table below shows the DISA STIG requirements that are not applicable. Many of them are out of scope because there is only one (locked down) user account, no graphical user interface and this guide does not require having a mail server set up for notifications. FIPS compliance can also only be achieved by using Ubuntu Pro, while this guide refers to the free version.

STIG ID Severity Rule Title Comment
UBTU-20-010000 medium The Ubuntu operating system must provision temporary user accounts with an expiration time of 72 hours or less. There are no temporary accounts.

UBTU-20-010002

medium

The Ubuntu operating system must enable the graphical user logon banner to display the Standard Mandatory DoD Notice and Consent Banner before granting local access to the system via a graphical user logon.

No GUI installed

UBTU-20-010003

medium

The Ubuntu operating system must display the Standard Mandatory DoD Notice and Consent Banner before granting local access to the system via a graphical user logon.

No GUI installed

UBTU-20-010004

medium

The Ubuntu operating system must retain a user’s session lock until that user re-establishes access using established identification and authentication procedures.

No GUI installed

UBTU-20-010006

high

The Ubuntu operating system must map the authenticated identity to the user or group account for PKI-based authentication.

Only one (locked down) user on the system.

UBTU-20-010010

medium

The Ubuntu operating system must uniquely identify interactive users.

There are no interactive users

UBTU-20-010033

medium

The Ubuntu operating system must implement smart card logins for multifactor authentication for local and network access to privileged and non-privileged accounts.

There are no interactive users

UBTU-20-010044

medium

The Ubuntu operating system must configure the SSH daemon to use FIPS 140-2 approved ciphers to prevent the unauthorized disclosure of information and/or detect changes to information during transmission.

SSH is disabled

UBTU-20-010060

medium

The Ubuntu operating system, for PKI-based authentication, must validate certificates by constructing a certification path (which includes status information) to an accepted trust anchor.

There are no interactive users

UBTU-20-010063

medium

The Ubuntu operating system must implement multifactor authentication for remote access to privileged accounts in such a way that one of the factors is provided by a device separate from the system gaining access.

There is no remote access to privileged accounts

UBTU-20-010064

medium

The Ubuntu operating system must accept Personal Identity Verification (PIV) credentials.

There are no interactive users and no smart cards

UBTU-20-010065

medium

The Ubuntu operating system must electronically verify Personal Identity Verification (PIV) credentials.

There are no interactive users and no smart cards

UBTU-20-010066

medium

The Ubuntu operating system for PKI-based authentication, must implement a local cache of revocation data in case of the inability to access revocation information via the network.

There are no interactive users and no smart cards

UBTU-20-010117

medium

The Ubuntu operating system must alert the ISSO and SA (at a minimum) in the event of an audit processing failure.

This guide does not require 3rd party services for notifications

UBTU-20-010215

low

The Ubuntu operating system must allocate audit record storage capacity to store at least one weeks’ worth of audit records, when audit records are not immediately sent to a central audit record storage facility.

Setting up configuration for audit storage

5GB are for /var/log/audit – as there should be almost nothing in the logs, this should be more than enough

We just use percentage value, we don’t have knowledge about customer audit volume.

UBTU-20-010216

low

The Ubuntu operating system audit event multiplexor must be configured to off-load audit logs onto a different system or storage media from the system being audited.

This guide does not require 3rd party services for notifications

UBTU-20-010217

low

The Ubuntu operating system must immediately notify the SA and ISSO (at a minimum) when allocated audit record storage volume reaches 75% of the repository maximum audit record storage capacity.

This guide does not require 3rd party services for notifications

UBTU-20-010300

low

The Ubuntu operating system must have a crontab script running weekly to offload audit events of standalone systems.

This guide does not require 3rd party services for notifications

UBTU-20-010409

medium

The Ubuntu operating system must disable account identifiers (individuals, groups, roles, and devices) after 35 days of inactivity.

There is only one (locked down) account

UBTU-20-010410

low

The Ubuntu operating system must automatically remove or disable emergency accounts after 72 hours.

There is only one (locked down) account

UBTU-20-010415

low

The Ubuntu operating system must deploy Endpoint Security for Linux Threat Prevention (ENSLTP).

This guide does not require 3rd party products

UBTU-20-010436

low

The Ubuntu operating system must synchronize internal information system clocks to the authoritative time source when the time difference is greater than one second.

See UBTU-20-010435. The assumption is, that an attacker could manipulate the NTP servers or network communication

UBTU-20-010437

medium

The Ubuntu operating system must notify designated personnel if baseline configurations are changed in an unauthorized manner. The file integrity tool must notify the System Administrator when changes to the baseline configuration or anomalies in the oper

Default system settings

 

We have no mail server configured

UBTU-20-010440

medium

The Ubuntu operating system must allow the use of a temporary password for system logons with an immediate change to a permanent password.

There is only one (locked down) account

UBTU-20-010441

low

The Ubuntu operating system must be configured such that Pluggable Authentication Module (PAM) prohibits the use of cached authentications after one day.

There are no cached credentials

UBTU-20-010442

high

The Ubuntu operating system must implement NIST FIPS-validated cryptography  to protect classified information and for the following: to provision digital signatures, to generate cryptographic hashes, and to protect unclassified information requiring confidentiality and cryptographic protection in accordance with applicable federal laws, Executive Orders, directives, policies, regulations, and standards.

Only Ubuntu Pro has that

UBTU-20-010443

medium

The Ubuntu operating system must only allow the use of DoD PKI-established certificate authorities for verification of the establishment of protected sessions.

There is only one (locked down) account

UBTU-20-010459

high

The Ubuntu operating system must disable the x86 Ctrl-Alt-Delete key sequence if a graphical user interface is installed.

No GUI installed.

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