CIS Amazon Linux 2023 Benchmark for Level 2 - Server
Rules and Groups employed by this XCCDF Profile
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Web Server
The web server is responsible for providing access to content via the HTTP protocol. Web servers represent a significant security risk because: <br> <br> <ul> <li>The HTTP port is commo...Group -
Disable Apache if Possible
If Apache was installed and activated, but the system does not need to act as a web server, then it should be disabled and removed from the system.Group -
Uninstall httpd Package
Thehttpd
package can be removed with the following command:$ sudo dnf remove httpd
Rule Unknown Severity -
Disable NGINX if Possible
If NGINX was installed and activated, but the system does not need to act as a web server, then it should be removed from the system.Group -
Uninstall nginx Package
Thenginx
package can be removed with the following command:$ sudo dnf remove nginx
Rule Unknown Severity -
IMAP and POP3 Server
Dovecot provides IMAP and POP3 services. It is not installed by default. The project page at <a href="http://www.dovecot.org">http://www.dovecot.org</a> contains more detailed information abou...Group -
Disable Cyrus IMAP
If the system does not need to operate as an IMAP or POP3 server, the Cyrus IMAP software should be removed.Group -
Uninstall cyrus-imapd Package
Thecyrus-imapd
package can be removed with the following command:$ sudo dnf remove cyrus-imapd
Rule Unknown Severity -
Disable Dovecot
If the system does not need to operate as an IMAP or POP3 server, the dovecot software should be disabled and removed.Group -
Uninstall dovecot Package
Thedovecot
package can be removed with the following command:$ sudo dnf remove dovecot
Rule Unknown Severity -
LDAP
LDAP is a popular directory service, that is, a standardized way of looking up information from a central database. Amazon Linux 2023 includes software that enables a system to act as both an LDAP ...Group -
Configure OpenLDAP Clients
This section provides information on which security settings are important to configure in OpenLDAP clients by manually editing the appropriate configuration files. Amazon Linux 2023 provides an a...Group -
Ensure LDAP client is not installed
The Lightweight Directory Access Protocol (LDAP) is a service that provides a method for looking up information from a central database. The <code>openldap-clients</code> package can be removed wit...Rule Low Severity -
Mail Server Software
Mail servers are used to send and receive email over the network. Mail is a very common service, and Mail Transfer Agents (MTAs) are obvious targets of network attack. Ensure that systems are not r...Group -
Ensure Mail Transfer Agent is not Listening on any non-loopback Address
Mail Transfer Agents (MTA), such as sendmail and Postfix, are used to listen for incoming mail and transfer the messages to the appropriate user or mail server. If the system is not intended to be ...Rule Medium Severity -
Configure SMTP For Mail Clients
This section discusses settings for Postfix in a submission-only e-mail configuration.Group -
Disable Postfix Network Listening
Edit the file <code>/etc/postfix/main.cf</code> to ensure that only the following <code>inet_interfaces</code> line appears: <pre>inet_interfaces = <xccdf-1.2:sub idref="xccdf_org.ssgproject.conten...Rule Medium Severity -
NFS and RPC
The Network File System is a popular distributed filesystem for the Unix environment, and is very widely deployed. This section discusses the circumstances under which it is possible to disable NF...Group -
Disable All NFS Services if Possible
If there is not a reason for the system to operate as either an NFS client or an NFS server, follow all instructions in this section to disable subsystems required by NFS.Group -
Disable Services Used Only by NFS
If NFS is not needed, disable the NFS client daemons nfslock, rpcgssd, and rpcidmapd. <br> <br> All of these daemons run with elevated privileges, and many listen for network connections. I...Group -
Disable rpcbind Service
The rpcbind utility maps RPC services to the ports on which they listen. RPC processes notify rpcbind when they start, registering the ports they are listening on and the RPC program numbers they e...Rule Low Severity -
Configure NFS Clients
The steps in this section are appropriate for systems which operate as NFS clients.Group -
Disable NFS Server Daemons
There is no need to run the NFS server daemons <code>nfs</code> and <code>rpcsvcgssd</code> except on a small number of properly secured systems designated as NFS servers. Ensure that these daemons...Group -
Disable Network File System (nfs)
The Network File System (NFS) service allows remote hosts to mount and interact with shared filesystems on the local system. If the local system is not designated as a NFS server then this service ...Rule Unknown Severity -
Network Time Protocol
The Network Time Protocol is used to manage the system clock over a network. Computer clocks are not very accurate, so time will drift unpredictably on unmanaged systems. Central time protocols can...Group -
A remote time server for Chrony is configured
<code>Chrony</code> is a daemon which implements the Network Time Protocol (NTP). It is designed to synchronize system clocks across a variety of systems and use a source that is highly accurate. M...Rule Medium Severity -
Ensure that chronyd is running under chrony user account
chrony is a daemon which implements the Network Time Protocol (NTP). It is designed to synchronize system clocks across a variety of systems and use a source that is highly accurate. More informati...Rule Medium Severity -
Obsolete Services
This section discusses a number of network-visible services which have historically caused problems for system security, and for which disabling or severely limiting the service has been the best a...Group -
Uninstall rsync Package
The rsyncd service can be used to synchronize files between systems over network links. The <code>rsync</code> package can be removed with the following command: <pre> $ sudo dnf remove rsync</pre>...Rule Medium Severity -
Rlogin, Rsh, and Rexec
The Berkeley r-commands are legacy services which allow cleartext remote access and have an insecure trust model.Group -
Remove Rsh Trust Files
The files <code>/etc/hosts.equiv</code> and <code>~/.rhosts</code> (in each user's home directory) list remote hosts and users that are trusted by the local system when using the rshd daemon. To re...Rule High Severity -
Telnet
The telnet protocol does not provide confidentiality or integrity for information transmitted on the network. This includes authentication information such as passwords. Organizations which use tel...Group -
Uninstall telnet-server Package
Thetelnet-server
package can be removed with the following command:$ sudo dnf remove telnet-server
Rule High Severity -
Remove telnet Clients
The telnet client allows users to start connections to other systems via the telnet protocol.Rule Low Severity -
TFTP Server
TFTP is a lightweight version of the FTP protocol which has traditionally been used to configure networking equipment. However, TFTP provides little security, and modern versions of networking oper...Group -
Uninstall tftp-server Package
Thetftp-server
package can be removed with the following command:$ sudo dnf remove tftp-server
Rule High Severity -
Print Support
The Common Unix Printing System (CUPS) service provides both local and network printing support. A system running the CUPS service can accept print jobs from other systems, process them, and send t...Group -
Uninstall CUPS Package
Thecups
package can be removed with the following command:$ sudo dnf remove cups
Rule Unknown Severity -
Proxy Server
A proxy server is a very desirable target for a potential adversary because much (or all) sensitive data for a given infrastructure may flow through it. Therefore, if one is required, the system ac...Group -
Disable Squid if Possible
If Squid was installed and activated, but the system does not need to act as a proxy server, then it should be disabled and removed.Group -
Uninstall squid Package
Thesquid
package can be removed with the following command:$ sudo dnf remove squid
Rule Unknown Severity -
Samba(SMB) Microsoft Windows File Sharing Server
When properly configured, the Samba service allows Linux systems to provide file and print sharing to Microsoft Windows systems. There are two software packages that provide Samba support. The firs...Group -
Disable Samba if Possible
Even after the Samba server package has been installed, it will remain disabled. Do not enable this service unless it is absolutely necessary to provide Microsoft Windows file and print sharing fun...Group -
Uninstall Samba Package
Thesamba
package can be removed with the following command:$ sudo dnf remove samba
Rule Unknown Severity -
SNMP Server
The Simple Network Management Protocol allows administrators to monitor the state of network devices, including computers. Older versions of SNMP were well-known for weak security, such as plaintex...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 is not needed, the software should be disabled an...Group -
Uninstall net-snmp Package
Thenet-snmp
package provides the snmpd service. Thenet-snmp
package can be removed with the following command:$ sudo dnf remove net-snmp
Rule Unknown Severity -
Disable snmpd Service
Thesnmpd
service can be disabled with the following command:$ sudo systemctl mask --now snmpd.service
Rule Low Severity -
SSH Server
The SSH protocol is recommended for remote login and remote file transfer. SSH provides confidentiality and integrity for data exchanged between two systems, as well as server authentication, throu...Group -
Verify Group Who Owns SSH Server config file
To properly set the group owner of/etc/ssh/sshd_config
, run the command:$ sudo chgrp root /etc/ssh/sshd_config
Rule Medium 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.