Guide to the Secure Configuration of Debian 12
Rules, Groups, and Values defined within the XCCDF Benchmark
-
Uninstall the telnet server
The telnet daemon should be uninstalled.Rule High Severity -
Configure DHCP Client if Necessary
If DHCP must be used, then certain configuration changes can minimize the amount of information it receives and applies from the network, and thus ...Group -
Configure DHCP Server
If the system must act as a DHCP server, the configuration information it serves should be minimized. Also, support for other protocols and DNS-upd...Group -
Restrict the Set of Users Allowed to Access FTP
This section describes how to disable non-anonymous (password-based) FTP logins, or, if it is not possible to do this entirely due to legacy applic...Group -
Limit Users Allowed FTP Access if Necessary
If there is a mission-critical reason for users to access their accounts via the insecure FTP protocol, limit the set of users who are allowed this...Rule Unknown Severity -
The Postfix package is installed
A mail server is required for sending emails. The <code>postfix</code> package can be installed with the following command: <pre> $ apt-get install...Rule Medium Severity -
Configure SMTP For Mail Clients
This section discusses settings for Postfix in a submission-only e-mail configuration.Group -
Postfix Network Interfaces
The setting for inet_interfaces in /etc/postfix/main.cfValue -
Postfix relayhost
Specify the host all outbound email should be routed into.Value -
Postfix Root Mail Alias
Specify an email address (string) for a root mail alias.Value -
Configure System to Forward All Mail For The Root Account
Make sure that mails delivered to root user are forwarded to a monitored email address. Make sure that the address <xccdf-1.2:sub idref="xccdf_org....Rule Medium Severity -
Configure System to Forward All Mail From Postmaster to The Root Account
Verify the administrators are notified in the event of an audit processing failure. Check that the "/etc/aliases" file has a defined value for "roo...Rule Medium Severity -
Configure System to Forward All Mail through a specific host
Set up a relay host that will act as a gateway for all outbound email. Edit the file <code>/etc/postfix/main.cf</code> to ensure that only the foll...Rule Medium Severity -
Configure NFS Servers
The steps in this section are appropriate for systems which operate as NFS servers.Group -
Ensure All-Squashing Disabled On All Exports
The <code>all_squash</code> maps all uids and gids to an anonymous user. This should be disabled by removing any instances of the <code>all_squash<...Rule Low Severity -
Vendor Approved Time pools
The list of vendor-approved pool serversValue -
Vendor Approved Time Servers
The list of vendor-approved time serversValue -
SNMP Server
The Simple Network Management Protocol allows administrators to monitor the state of network devices, including computers. Older versions of SNMP w...Group -
Disable SNMP Server if Possible
The system includes an SNMP daemon that allows for its remote monitoring, though it not installed by default. If it was installed and activated but...Group -
Disable snmpd Service
Thesnmpd
service can be disabled with the following command:$ sudo systemctl mask --now snmpd.service
Rule Low Severity -
SNMP read-only community string
Specify the SNMP community string used for read-only access.Value -
SNMP read-write community string
Specify the SNMP community string used for read-write access.Value -
Ensure Default SNMP Password Is Not Used
Edit <code>/etc/snmp/snmpd.conf</code>, remove or change the default community strings of <code>public</code> and <code>private</code>. This profil...Rule High Severity -
Allow Only SSH Protocol 2
Only SSH protocol version 2 connections should be permitted. The default setting in <code>/etc/ssh/sshd_config</code> is correct, and can be verifi...Rule High Severity -
Limit Users' SSH Access
By default, the SSH configuration allows any user with an account to access the system. There are several options available to limit which users an...Rule Unknown Severity -
Ensure SSH LoginGraceTime is configured
The <code>LoginGraceTime</code> parameter to the SSH server specifies the time allowed for successful authentication to the SSH server. The longer ...Rule Medium Severity -
Set LogLevel to INFO
The INFO parameter specifices that record login and logout activity will be logged. <br> The default SSH configuration sets the log level to INFO. ...Rule Low Severity -
Set SSH Daemon LogLevel to VERBOSE
The <code>VERBOSE</code> parameter configures the SSH daemon to record login and logout activity. To specify the log level in SSH, add or correct t...Rule Medium Severity -
Set SSH authentication attempt limit
The <code>MaxAuthTries</code> parameter specifies the maximum number of authentication attempts permitted per connection. Once the number of failur...Rule Medium Severity -
Set SSH MaxSessions limit
The <code>MaxSessions</code> parameter specifies the maximum number of open sessions permitted from a given connection. To set MaxSessions edit <co...Rule Medium Severity -
Action for auditd to take when disk space just starts to run low
The setting for space_left_action in /etc/audit/auditd.confValue -
Ensure All User Initialization Files Have Mode 0740 Or Less Permissive
Set the mode of the user initialization files to <code>0740</code> with the following command: <pre>$ sudo chmod 0740 /home/<i>USER</i>/.<i>INIT_FI...Rule Medium Severity -
Verify the UEFI Boot Loader grub.cfg User Ownership
The file <code>/boot/grub2/grub.cfg</code> should be owned by the <code>root</code> user to prevent destruction or modification of the file. To pr...Rule Medium Severity -
Enable cron Service
The <code>crond</code> service is used to execute commands at preconfigured times. It is required by almost all systems to perform necessary mainte...Rule Medium Severity -
Verify /boot/grub2/user.cfg User Ownership
The file <code>/boot/grub2/user.cfg</code> should be owned by the <code>root</code> user to prevent reading or modification of the file. To proper...Rule Medium Severity -
Verify the UEFI Boot Loader grub.cfg Permissions
File permissions for <code>/boot/grub2/grub.cfg</code> should be set to 700. To properly set the permissions of <code>/boot/grub2/grub.cfg</code>,...Rule Medium Severity -
Verify /boot/grub2/user.cfg Permissions
File permissions for <code>/boot/grub2/user.cfg</code> should be set to 600. To properly set the permissions of <code>/boot/grub2/user.cfg</code>,...Rule Medium Severity -
Verify Permissions on shadow File
To properly set the permissions of/etc/shadow
, run the command:$ sudo chmod 0640 /etc/shadow
Rule Medium Severity -
Verify Permissions on /etc/shells File
To properly set the permissions of/etc/shells
, run the command:$ sudo chmod 0644 /etc/shells
Rule Medium Severity -
Verify Group Who Owns /var/log Directory
To properly set the group owner of/var/log
, run the command:$ sudo chgrp root /var/log
Rule Medium Severity -
Verify Group Who Owns /var/log/messages File
To properly set the group owner of/var/log/messages
, run the command:$ sudo chgrp root /var/log/messages
Rule Medium Severity -
Verify Group Who Owns /var/log/syslog File
To properly set the group owner of/var/log/syslog
, run the command:$ sudo chgrp adm /var/log/syslog
Rule Medium Severity -
Verify User Who Owns /var/log Directory
To properly set the owner of/var/log
, run the command:$ sudo chown root /var/log
Rule Medium Severity -
Verify User Who Owns /var/log/messages File
To properly set the owner of/var/log/messages
, run the command:$ sudo chown root /var/log/messages
Rule Medium Severity -
Verify User Who Owns /var/log/syslog File
To properly set the owner of/var/log/syslog
, run the command:$ sudo chown syslog /var/log/syslog
Rule Medium Severity -
Verify Permissions on /var/log/messages File
To properly set the permissions of/var/log/messages
, run the command:$ sudo chmod 0640 /var/log/messages
Rule Medium Severity -
Verify Permissions on /var/log/syslog File
To properly set the permissions of/var/log/syslog
, run the command:$ sudo chmod 0640 /var/log/syslog
Rule Medium Severity -
DHCP
The Dynamic Host Configuration Protocol (DHCP) allows systems to request and obtain an IP address and other configuration parameters from a server....Group -
Ensure the Logon Failure Delay is Set Correctly in login.defs
To ensure the logon failure delay controlled by <code>/etc/login.defs</code> is set properly, add or correct the <code>FAIL_DELAY</code> setting in...Rule Medium Severity -
Disable Network File Systems (netfs)
The netfs script manages the boot-time mounting of several types of networked filesystems, of which NFS and Samba are the most common. If these fil...Rule Unknown Severity
Node 2
The content of the drawer really is up to you. It could have form fields, definition lists, text lists, labels, charts, progress bars, etc. Spacing recommendation is 24px margins. You can put tabs in here, and can also make the drawer scrollable.