AlmaLinux 8.10
Overview
AlmaLinux is a community-owned enterprise Linux distribution, produced by the AlmaLinux OS Foundation to be binary compatible with Red Hat Enterprise Linux 8. Version 8.10 is the final minor release in the RHEL 8 family, so there is no 8.11. AlmaLinux 8 remains supported until 2029, and security backports continue to flow into the 8.10 maintenance stream. A fully updated machine still reports release 8.10 while carrying current fixes.
This guide covers deploying and configuring AlmaLinux 8.10 on Microsoft Azure, using SecureAnyCloud's preconfigured virtual machine image from the Azure Marketplace.
What you get:
- AlmaLinux 8.10, binary compatible with RHEL 8
- Every available 8.10 maintenance stream update applied at build time
- dnf-automatic armed, so the machine keeps applying security updates on its own
- Azure Linux Agent (waagent) and cloud-init for Azure integration
- Chronyd for NTP time synchronization
- SELinux in enforcing mode
- BaseOS, AppStream and Extras repositories enabled, so your update path stays intact
- Gen2 Hyper-V virtual machine support
- 24/7 SecureAnyCloud support
Platform: Microsoft Azure (Gen2 Hyper-V). Default user: azureuser.
Security posture
This image ships with no known credential. There is no default password and no baked-in SSH key.
- Root is locked. The root account password is locked, so no one can log in as root with a password.
- Key-only SSH.
PasswordAuthenticationis disabled in the SSH daemon, so every login is by key. - Root login restricted.
PermitRootLoginis set toprohibit-password, so root cannot be reached with a password even if one is set later. - Your key only. The only key that works is the public key you supply when you create the virtual machine. Azure injects it into
azureuserat first boot, so no two machines you launch ever share a secret. - Per-instance identity. The machine identity and the SSH host keys are regenerated uniquely on every instance, so no two machines share a host key either.
- SELinux enforcing. SELinux stays in enforcing mode, the AlmaLinux default.
Prerequisites
Before you deploy this image, make sure you have:
- An active Microsoft Azure subscription
- Access to the Azure Portal or Azure CLI
- An SSH key pair for Linux VM access
- Familiarity with Azure VM management
Recommended VM size: Standard_B2s (2 vCPU, 4 GB RAM) or larger.
Deploy the virtual machine
Option A: Azure Portal
- Open the Azure Marketplace and search for "AlmaLinux 8.10 SecureAnyCloud".
- Select the image and choose Create.
- On the Basics tab, set Subscription to your Azure subscription, Resource Group to a new or existing group, Virtual Machine Name to a name for your VM, Region to your preferred Azure region, and Size to
Standard_B2s(recommended). - Under Administrator Account, select SSH public key and enter your key.
- Under Inbound Port Rules, allow SSH (port 22).
- Select Review + Create, then Create.
Option B: Azure CLI
az vm image terms accept --urn sac1647283583153:almalinux-8-10:default:latest
az vm create \
--resource-group myResourceGroup \
--name my-almalinux-8-10-vm \
--image sac1647283583153:almalinux-8-10:default:latest \
--size Standard_B2s \
--admin-username azureuser \
--generate-ssh-keys \
--public-ip-sku StandardConnect via SSH
Run these commands on your own workstation, not on the VM. Find the public IP, then connect:
az vm show --resource-group myResourceGroup --name my-almalinux-8-10-vm --show-details --query publicIps -o tsv ssh azureuser@<vm-ip>There is no password to enter. If SSH asks for one, your client is not offering the key you supplied at create time.
Confirm the release
Check that the machine is the AlmaLinux 8.10 release you expect:
cat /etc/almalinux-release grep -E '^(NAME|VERSION|ID|PLATFORM_ID)=' /etc/os-release uname -rmExpected output:
AlmaLinux release 8.10 (Cerulean Leopard) NAME="AlmaLinux" VERSION="8.10 (Cerulean Leopard)" ID="almalinux" PLATFORM_ID="platform:el8" 4.18.0-553.153.1.el8_10.x86_64 x86_64The kernel version carries an el8_10 tag. This tag shows that the machine tracks the 8.10 maintenance stream rather than an older 8 series minor release.
Check the patch level
The image is fully updated at build time. dnf check-update returns exit code 100 when updates are pending and 0 when none are. Check now:
sudo dnf check-update echo "exit code: $?"List the enabled repositories to confirm your update path is intact:
dnf repolist --enabledExpected output:
repo id repo name appstream AlmaLinux 8 - AppStream baseos AlmaLinux 8 - BaseOS extras AlmaLinux 8 - ExtrasBecause 8.10 is the last minor release in the RHEL 8 family, applying updates keeps you on 8.10 rather than moving you to a new point release.
This image also arms dnf-automatic, so security updates are downloaded and applied on a timer without any action from you. You can still run updates on your own schedule:
sudo dnf upgrade -yReboot if a new kernel was installed:
sudo systemctl rebootVerify the security posture
Confirm that SELinux is enforcing, root is locked and SSH is key-only:
getenforce
sudo passwd -S root
sudo sshd -T | grep -E '^(permitrootlogin|passwordauthentication|pubkeyauthentication)'Expected output:
Enforcing root LK 2009-12-22 -1 -1 -1 -1 (Alternate authentication scheme in use.) permitrootlogin without-password pubkeyauthentication yes passwordauthentication nowithout-password is how OpenSSH reports the prohibit-password setting. Both names mean the same thing: root may not authenticate with a password.
Verify Azure integration and unattended updates
Confirm that the Azure Linux Agent, cloud-init and time synchronization are healthy and that unattended security updates are armed. The last two commands show your disk and memory resources:
systemctl is-active waagent
systemctl is-enabled waagent cloud-init --version
systemctl is-enabled dnf-automatic.timer
systemctl is-active chronyd df -h / free -hwaagent lets Azure provision your SSH key, resize the OS disk, run extensions and report VM health, so it should always be active and enabled. An enabled dnf-automatic.timer keeps the machine applying security updates on its own after launch.
Networking and the firewall
The Azure Network Security Group (NSG) controls inbound and outbound traffic. It is the first, and usually the only, place you need to open a port. The image advertises a single inbound port, SSH on 22.
firewalld is installed on this image but left inactive and disabled. It does not filter traffic by default, so your NSG rules take effect exactly as written, with no second layer to keep in sync.
Confirm what is listening before you open anything:
ss -tlnpOn a fresh machine, the listeners are sshd on port 22 and rpcbind on port 111, a local RPC helper. Only port 22 is advertised for inbound access, and the Azure NSG governs what is reachable from outside.
If your policy also requires a host firewall, enable the one that is already installed:
sudo systemctl enable --now firewalld
sudo firewall-cmd --permanent --add-service=ssh sudo firewall-cmd --permanent --add-port=443/tcp sudo firewall-cmd --reloadOnce firewalld is running, a port must be open in both the Azure NSG and firewalld before traffic reaches your service. Add the SSH service first, as shown above, so that enabling the firewall does not lock you out.
Install software
AppStream carries the application packages. Search it, then install what you need:
dnf search nginxAlmaLinux 8 uses modules. AppStream ships several versions of the same language or database as separate streams, so you can pick a version rather than take the default:
dnf module list nginxInstall a package and enable it in the usual way, for example sudo dnf install -y nginx followed by sudo systemctl enable --now nginx.
To add another administrator, create the account with sudo adduser <name> and add it to the wheel group with sudo usermod -aG wheel <name>. Then copy your public key into /home/<name>/.ssh/authorized_keys with mode 600, and set the .ssh directory to mode 700, owned by that user.
The image ships with no human accounts at all, so azureuser is the only login until you add one. Check the wheel group:
getent group wheelCommon use cases
- RHEL 8-compatible application hosting
- Long-lived enterprise server workloads
- A base for software certified on the 8 platform
- A migration target for CentOS 8 estates
Troubleshooting
Cannot connect via SSH
- Verify that the VM is in the Running state in the Azure Portal.
- Check that port 22 is allowed in the Network Security Group.
- Make sure you are using the correct username:
azureuser. - Verify that your SSH key matches the one you supplied at create time. Password login is disabled by design, so a wrong key cannot fall back to a password prompt.
To see which key your client is offering, run ssh -v azureuser@<vm-ip> from your workstation and look for the Offering public key lines.
Azure agent not running
Check the agent status:
sudo systemctl status waagentIf it is not running, start it on the VM:
sudo systemctl enable --now waagentPackage manager issues
Refresh the metadata cache first:
sudo dnf clean all
sudo dnf makecacheIf repositories are unreachable, check DNS resolution. This image is minimal, so nslookup and dig are not installed. getent is always present and resolves through the same system resolver:
getent hosts repo.almalinux.orgInstall bind-utils if you want dig and nslookup.
A service is blocked and the logs mention SELinux
SELinux is enforcing on this image. Rather than disabling it, look at what was denied. On a healthy machine there are no recent denials, so the command reports none:
sudo ausearch -m AVC -ts recent 2>/dev/null || echo "no recent AVC denials"Important notes
AlmaLinux is free and open source. It is not covered by a single licence. It is a distribution assembled from thousands of independently packaged components, each with its own terms, including the GPL, LGPL, MIT, BSD, Apache 2.0 and MPL. You can read every package's terms with rpm -qi <package> and under /usr/share/licenses/. No subscription, licence key or Red Hat entitlement is required.
AlmaLinux 8 is supported until 2029. Plan a move to an AlmaLinux 9 or 10 image before that date for workloads that need to outlive it.
AlmaLinux is a trademark of the AlmaLinux OS Foundation. The name is used here nominatively, only to identify the distribution this image contains. SecureAnyCloud is not affiliated with, endorsed by or sponsored by the AlmaLinux OS Foundation.
Support
For assistance with this image, contact SecureAnyCloud support:
- Website: secureanycloud.com
- Product catalogue: secureanycloud.com/products
- User guides: secureanycloud.com/guides
- SLA: 24 hour response guaranteed
Deploy on Azure
Launch AlmaLinux 8.10 on Azure with 24/7 support from SecureAnyCloud.
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Overview
AlmaLinux 8 is a free, community-built enterprise Linux distribution that is binary compatible with Red Hat Enterprise Linux 8, with security updates until 2029. 8.10 is its final minor release.
This guide covers launching and verifying the AlmaLinux 8.10 AMI from SecureAnyCloud on Amazon EC2. It is one version of the SecureAnyCloud AlmaLinux listing on AWS Marketplace. You choose it as the software version when you subscribe and launch. Every release and variant in the listing is described at /guides/almalinux-aws/.
This is the standard AlmaLinux 8.10 version of the listing: the full AlmaLinux 8.10 for EC2 package set, with nothing trimmed.
What you get:
- The standard server package set, with current AWS tools. Everything the AlmaLinux 8.10 EC2 image ships stays installed. This includes the
tunedtuning daemon (running thevirtual-guestprofile), thelinux-firmwarebundle and the GeoLite2 location databases, which the Minimal version of this listing removes (Step 4). EC2 Instance Connect is removed (see Step 11), because the base image carried it as an unsigned package from outside the AlmaLinux repositories. The Systems Manager agent is brought to its current release. - CIS Level 1 Server remediation. The image is remediated with the OpenSCAP CIS Level 1 Server profile from SCAP Security Guide 0.1.82 (AlmaLinux's own signed
scap-security-guidepackage), then rebooted and evaluated. On this build all 294 scored rules pass (100.0%). Eight rules are waived because they cannot work on an EC2 image, each with its reason. The HTML report, the machine-readable results, the waiver list and a summary ship in/usr/share/doc/sac/. - EC2 defaults that keep you in control. Key-only SSH as
ec2-user, root locked, no password on any account, SELinux enforcing, IMDSv2 required, a host firewall (firewalld) that allows SSH in and everything out, the current AWS Systems Manager agent, and time from the Amazon Time Sync Service. - Fully patched at build time, with
dnf-automaticapplying security updates on your instance.
What is on the image: AlmaLinux 8.10 (the RHEL 8-compatible 4.18 kernel), cloud-init, OpenSSH, firewalld, chrony, tuned, SELinux (targeted policy, enforcing), the AWS Systems Manager agent, auditd, rsyslog, AIDE file integrity checking, dnf-automatic, Python 3.6, OpenSCAP and the pinned SCAP Security Guide content used for the evaluation.
Default user: ec2-user. Architecture: x86_64. Boot mode: UEFI (preferred). Root volume: 10 GiB gp3, XFS (grows to the size you choose at launch).
Standard or Minimal? Both versions are built the same way on the same day, carry the same hardening and score the same. Choose this standard version if you want the image as AlmaLinux ships it, with tuned applying its virtual-guest tuning. Choose AlmaLinux 8 Minimal if you want the smallest package set and do not need tuned, the hardware firmware bundle or the GeoLite2 databases. Choose AlmaLinux 8 LVM if your benchmark needs separate volumes for /tmp, /var, /var/log and the other CIS mount points.
These images are remediated with an OpenSCAP profile and ship their own evaluation report. They are not CIS Hardened Images, and CIS has not reviewed or certified them.
Connecting to your instance
Version SSH user Root device
AlmaLinux 8.10 ec2-user /dev/sda1 (10 GiB gp3)
Security posture
- No known credential. There is no default password and no baked-in SSH key. The only key that works is the EC2 key pair you choose at launch, which cloud-init installs for
ec2-useron first boot. The SSH server has no other way to look up keys (noAuthorizedKeysCommand). - Key-only SSH.
PasswordAuthentication no,PermitRootLogin no, challenge-response off. The root account has no password and is locked. - Per-instance identity. SSH host keys and the machine ID are generated fresh on every instance, so no two instances share a host key. The private host keys are readable by root only.
- IMDSv2 required. The AMI is registered with
ImdsSupport v2.0, so instances launched from it refuse token-less (IMDSv1) metadata requests by default. - SELinux enforcing with the targeted policy, as AlmaLinux ships it.
- Host firewall. firewalld's
publiczone allows only SSH and the DHCPv6 client inbound and allows all outbound traffic, so the SSM agent, metadata service, DNS, time and package updates keep working. - Only SSH listens on the network. Nothing else on the image listens on any address.
Prerequisites
- An AWS account and permission to launch EC2 instances
- An EC2 key pair in the Region you launch in
- A security group that allows TCP 22 from your own address, not from the whole internet
Recommended instance type: m5.large. The image runs on any current x86_64 instance type.
Launch the instance
Option A: AWS Marketplace console
- Open the SecureAnyCloud AlmaLinux listing on AWS Marketplace, choose View purchase options, then choose Subscribe. One subscription covers every version in the listing.
- When the subscription is active, choose Launch your software.
- Choose One-click launch from AWS Marketplace, or Launch from EC2 Console for full control. In Version, choose AlmaLinux 8.10 - YYYY-MM-DD (the date is when the version was added), and select your Region.
- Instance type: choose
m5.large(recommended). Any current x86_64 type works. The software charge is $0.04 per vCPU per hour. - Key pair: choose your EC2 key pair. It is the only way in. RSA and ED25519 keys both work.
- Security group: allow inbound TCP 22 from your own IP address or network only.
- Storage: the root volume is 10 GiB gp3 by default. Choose a larger size if you need one. cloud-init grows the root partition and filesystem to fill it on first boot.
- Metadata: leave the defaults, because the image already requires IMDSv2. Then choose Launch.
Option B: AWS CLI
Run this command on your own workstation. Replace the AMI ID with the one shown for your Region on the Marketplace launch page, and replace the key pair, security group and subnet with your own. The root device of this AMI is /dev/sda1:
aws ec2 run-instances \
--image-id ami-0123456789abcdef0 \
--instance-type m5.large \
--key-name my-key-pair \
--security-group-ids sg-0123456789abcdef0 \
--subnet-id subnet-0123456789abcdef0 \
--block-device-mappings 'DeviceName=/dev/sda1,Ebs={VolumeSize=20,VolumeType=gp3}' \
--tag-specifications 'ResourceType=instance,Tags=[{Key=Name,Value=almalinux-8-10}]'You do not need --metadata-options: the AMI already makes IMDSv2 required.
Connect via SSH
From your workstation, connect as ec2-user with the key pair you chose:
ssh -i ~/.ssh/my-key-pair.pem ec2-user@<public-ip>There is no password to enter. If SSH asks for one, or says Too many authentication failures, see Troubleshooting below.
You can also connect without opening port 22 at all, through AWS Systems Manager Session Manager, if the instance has an instance profile that allows Systems Manager. The agent is installed and running on this image.
First boot: apply the security updates released since the image was built, then reboot. dnf-automatic installs security updates once a day, kernels included, but a new kernel runs only after a reboot. Do this once before you put the instance into service:
sudo dnf -y upgrade --security sudo systemctl rebootReconnect after about a minute. uname -r then shows the new kernel if one was installed. Step 10 covers the patch level in detail.
Confirm the release
Check that the instance is the AlmaLinux 8.10 release you expect:
cat /etc/almalinux-release grep -E '^(NAME|VERSION|ID|VERSION_ID|PLATFORM_ID|PRETTY_NAME)=' /etc/os-release uname -srmExpected output:
AlmaLinux release 8.10 (Cerulean Leopard) NAME="AlmaLinux" VERSION="8.10 (Cerulean Leopard)" ID="almalinux" VERSION_ID="8.10" PLATFORM_ID="platform:el8" PRETTY_NAME="AlmaLinux 8.10 (Cerulean Leopard)" Linux 4.18.0-553.176.1.el8_10.x86_64 x86_64This version stays on 8.10. 8.10 is the final minor release of AlmaLinux 8, so there will be no 8.11. The repositories use the AlmaLinux 8 release stream ($releasever is 8), and the AlmaLinux mirror list serves that stream from the 8.10 tree. Updates keep arriving as ordinary 8.10 packages through dnf until AlmaLinux 8 reaches its end of life in 2029.
Your kernel version may be newer if updates have installed since this image was built.
The standard package set
This version keeps the AlmaLinux 8.10 EC2 package set whole. The packages that the Minimal version removes are installed here, and tuned is running. Verify:
rpm -qa | wc -l rpm -q tuned linux-firmware geolite2-city geolite2-country systemctl is-active tuned tuned-adm activeExpected output (the package versions change over time):
409 tuned-2.22.1-7.el8_10.noarch linux-firmware-20260908-145.gite981caea.el8_10.noarch geolite2-city-20180605-1.el8.noarch geolite2-country-20180605-1.el8.noarch active Current active profile: virtual-guest- tuned is the system tuning daemon. Its
virtual-guestprofile, the onetuned-adm recommendpicks on EC2, sets memory writeback and swappiness, disk readahead and CPU performance settings for a guest on a hypervisor. To use another profile, list the profiles withtuned-adm listand switch with, for example,sudo tuned-adm profile throughput-performance. - linux-firmware holds firmware for physical network, storage and graphics hardware. EC2 instances do not load it, but it is part of the AlmaLinux package set and takes about 1.6 GB of the root volume.
- geolite2-city and geolite2-country are IP geolocation databases that some tools can use.
- The
sossupport-report collector is not part of the AlmaLinux 8 EC2 base image. If a support engineer asks for a report, install it withsudo dnf -y install sosand runsudo sos report.
What the Minimal version drops. AlmaLinux 8 Minimal removes linux-firmware, geolite2-city, geolite2-country and tuned, and lists the removals in /usr/share/doc/sac/minimal-manifest.txt on its own image. A new Minimal instance built the same day has 405 packages against 409 here.
Everything else is the same in both versions. The AlmaLinux 8.10 EC2 base image is already small, so neither version has wireless or sound firmware, Cockpit or Plymouth installed. Both carry the same hardening, compliance tooling and AWS agents. The package count on your instance moves by a few as kernels and updates install.
Read the compliance evidence
The evaluation that the build ran after its reboot ships on the image. List the files and print the summary:
ls -lh /usr/share/doc/sac/ python3 -c "import json; s=json.load(open('/usr/share/doc/sac/cis-l1-summary.json')); print('profile: ', s['profileLabel'], '(SCAP Security Guide', s['ssgVersion'] + ')'); print('scored rules: ', s['scored'], ' pass:', s['pass'], ' fail:', s['fail'], ' rate:', str(s['ratePct']) + '%'); print('waived: ', s['waived'], ' not applicable:', s['notapplicable']); print('evaluated at: ', s['evaluatedAt'])"Expected output:
total 38M -rw-r--r--. 1 root root 36M Oct 19 23:36 cis-l1-arf.xml -rw-r--r--. 1 root root 2.4M Oct 19 23:36 cis-l1-report.html -rw-r--r--. 1 root root 1.2K Oct 19 23:36 cis-l1-summary.json -rw-r--r--. 1 root root 2.0K Oct 19 23:36 cis-l1-tailoring.xml -rw-r--r--. 1 root root 3.2K Oct 19 23:36 cis-l1-waivers.txt -rw-r--r--. 1 root root 1.6K Oct 19 23:29 scap-security-guide-LICENSE.txt profile: CIS Level 1 Server (SCAP Security Guide 0.1.82) scored rules: 294 pass: 294 fail: 0 rate: 100.0% waived: 8 not applicable: 38 evaluated at: 2026-10-19T23:36:36Zcis-l1-report.htmlis the full OpenSCAP report, rule by rule. Copy it to your workstation and open it in a browser.cis-l1-arf.xmlis the same evaluation in the machine-readable ARF format, for compliance tooling.cis-l1-tailoring.xmlis the exact tailoring used, so you can re-run the same evaluation (Step 6).- The pass rate is pass / (pass + fail + error + unknown). Rules that are not applicable to this machine, not selected or waived are not counted.
To copy the report to your workstation, run this command on the workstation:
scp -i ~/.ssh/my-key-pair.pem ec2-user@<public-ip>:/usr/share/doc/sac/cis-l1-report.html .The eight waived rules
List the waived rules:
grep -v '^#' /usr/share/doc/sac/cis-l1-waivers.txt | cut -f1,2Expected output:
partition_for_tmp [single-volume-partitions] grub2_password [serial-console-and-boot] grub2_uefi_password [serial-console-and-boot] ensure_root_password_configured [serial-console-and-boot] accounts_maximum_age_login_defs [key-only-account-aging] account_disable_post_pw_expiration [key-only-account-aging] sshd_limit_user_access [ssh-access-list] service_systemd-journal-upload_enabled [log-remote-destination]The full reason for each is the third column of the same file. In short:
- Separate /tmp partition. This version boots from one EBS root volume. The LVM versions of this listing provide separate volumes for /tmp, /var, /var/log, /var/log/audit, /var/tmp and /home.
- Boot loader and root passwords. A GRUB or root password would have to be baked into the image, giving every instance the same secret. Root stays locked with no password. Set your own if you need serial console access (see Step 11).
- Password ageing defaults. The accounts cloud-init creates are key-only. An ageing limit would expire them and lock the SSH key out. Accounts that do have a password are still aged.
- SSH AllowUsers/AllowGroups. A list fixed at build time would refuse accounts you create later. Your security group restricts who can reach port 22.
- Remote journal upload. The benchmark switches on
systemd-journal-upload, which sends the system journal to a remote log server, but the image cannot know your log server. Switched on with no destination, the service fails at every boot.systemd-journal-remoteis installed and the upload service is left off. To use it, see "Send the journal to your own log server" below.
Every scored rule passes
Print the list of failing rules:
python3 -c "import json; print(json.load(open('/usr/share/doc/sac/cis-l1-summary.json'))['failingRules'])"Expected output:
[]The list of failing rules is empty, so every rule the profile scores on this image passes. Rules that do not apply to an EC2 instance, for example wireless interfaces, are reported as not applicable and are not counted.
Send the journal to your own log server
If you run a systemd-journal-remote collector, point the image at it and switch the upload service on. Replace the address with your collector's:
echo 'URL=https://logs.example.internal:19532' | sudo tee -a /etc/systemd/journal-upload.conf
sudo systemctl enable --now systemd-journal-uploadRe-run the evaluation yourself
You can repeat the evaluation at any time with the same content and tailoring. It takes about a minute. Run it:
sudo oscap xccdf eval \
--tailoring-file /usr/share/doc/sac/cis-l1-tailoring.xml \
--profile xccdf_co.sac_profile_cis-l1_ec2_single \
--results /tmp/cis-check-results.xml --report /tmp/cis-check-report.html \
/usr/share/xml/scap/ssg/content/ssg-almalinux8-ds.xml > /tmp/cis-check.log 2>&1 echo "oscap exit code: $? (0 = every rule passed, 2 = at least one rule did not pass)"
sudo python3 -c "import re,collections; c=collections.Counter(re.findall(r'<result>(\w+)</result>', open('/tmp/cis-check-results.xml').read())); s=sum(c[k] for k in ('pass','fail','error','unknown')); print(dict(sorted(c.items()))); print('pass rate: %.1f%%' % (100.0*c['pass']/s))"Expected output:
oscap exit code: 0 (0 = every rule passed, 2 = at least one rule did not pass) {'notapplicable': 38, 'notselected': 1369, 'pass': 294} pass rate: 100.0%Your own report is at /tmp/cis-check-report.html. As you install software and change settings, re-run the evaluation to see how your changes affect the result.
Confirm IMDSv2 is required
Send a metadata request without a token, then repeat it with a session token:
curl -s -o /dev/null -w 'IMDSv1 request without a token: HTTP %{http_code}\n' http://169.254.169.254/latest/meta-data/instance-id
TOKEN=$(curl -s -X PUT -H 'X-aws-ec2-metadata-token-ttl-seconds: 60' http://169.254.169.254/latest/api/token)
curl -s -H "X-aws-ec2-metadata-token: $TOKEN" -w '\n' http://169.254.169.254/latest/meta-data/placement/regionExpected output (your Region may differ):
IMDSv1 request without a token: HTTP 401 us-east-1A request without a session token is refused with HTTP 401, and the same request with a token works. Scripts and SDKs on the instance must use IMDSv2. Every current AWS SDK and the AWS CLI do this automatically.
The host firewall and listening ports
Check the firewall state, the active rules and the listening ports:
sudo firewall-cmd --state sudo firewall-cmd --list-all sudo ss -tlnpExpected output:
running public (active) target: default icmp-block-inversion: no interfaces: eth0 sources: services: dhcpv6-client ssh ports: protocols: forward: no masquerade: no forward-ports: source-ports: icmp-blocks: rich rules: State Recv-Q Send-Q Local Address:Port Peer Address:PortProcess LISTEN 0 128 0.0.0.0:22 0.0.0.0:* users:(("sshd",pid=849,fd=3)) LISTEN 0 128 [::]:22 [::]:* users:(("sshd",pid=849,fd=4))- Only
sshdlistens, on port 22. Nothing else on the image opens a TCP port. - The
publiczone allowssshanddhcpv6-client. The DHCPv6 client receives replies from the IPv6 DHCP server, which is how an instance in an IPv6-enabled subnet gets its address. The AlmaLinux defaultcockpitservice is removed from the zone, and Cockpit is not installed. - The loopback interface sits in firewalld's
trustedzone, with rules that drop traffic claiming a loopback source from anywhere else (a CIS requirement).
To open a port for your own service, take two steps. Allow the port in the instance's security group, and allow it in firewalld. For example, for a web server on 443, run this on the instance:
sudo firewall-cmd --permanent --add-service=https sudo firewall-cmd --reloadIf a port is open in the security group but not in firewalld, or the other way round, the traffic does not arrive.
Time sync and the Systems Manager agent
Check the time and Systems Manager services, then list the time sources:
systemctl is-active chronyd amazon-ssm-agent chronyc -n sourcesExpected output (the pool servers and timings vary):
active active MS Name/IP address Stratum Poll Reach LastRx Last sample =============================================================================== ^- 23.172.120.58 2 6 17 43 +443us[ +488us] +/- 56ms ^- 97.107.136.23 2 6 17 44 +123us[ +168us] +/- 7586us ^- 139.177.202.26 2 6 17 43 -4318us[-4273us] +/- 75ms ^- 23.157.100.123 2 6 17 43 -572us[ -527us] +/- 34ms ^* 169.254.169.123 3 4 77 11 +1945ns[ +123us] +/- 522usThe ^* marks the source that chrony is using: 169.254.169.123, the Amazon Time Sync Service. It is reachable from every instance without internet access, so time stays correct in a private subnet too. The public AlmaLinux pool servers are fallbacks.
The AWS Systems Manager agent is installed from Amazon's own package at its current release (3.3.5390.0 on this build). It is not in the AlmaLinux repositories, so dnf does not update it. Systems Manager can keep it current for you, through the AWS-UpdateSSMAgent document or the Auto update SSM Agent setting in Fleet Manager.
Patch level and automatic updates
The image is fully patched at build time. Check what is pending now:
sudo dnf -q check-update --refresh echo "dnf check-update exit code: $? (0 = nothing to update, 100 = updates available)" grep -E '^(upgrade_type|apply_updates)' /etc/dnf/automatic.conf systemctl is-enabled dnf-automatic.timer uname -rExpected output on an instance launched soon after the image was built (later launches list the updates released since, with exit code 100):
dnf check-update exit code: 0 (0 = nothing to update, 100 = updates available) upgrade_type = security apply_updates = yes enabled 4.18.0-553.176.1.el8_10.x86_64dnf-automatic runs daily (06:00, with a random delay of up to an hour) and installs security updates automatically. To update everything now, run:
sudo dnf -y upgradednf-automatic installs a new kernel but does not reboot, so the running kernel stays the old one until you reboot. Reboot if a new kernel was installed:
sudo systemctl rebootSecurity settings on the instance
Check SELinux, the root account, the SSH settings, the login banner, EC2 Instance Connect and the host key permissions:
getenforce
sudo passwd -S root
sudo sshd -T | grep -E '^(permitrootlogin|passwordauthentication|pubkeyauthentication|maxauthtries|clientaliveinterval|banner|authorizedkeyscommand) ' cat /etc/issue.net rpm -q --quiet ec2-instance-connect && echo "EC2 Instance Connect: installed" || echo "EC2 Instance Connect: not installed"
sudo ls -l /etc/ssh/ssh_host_ecdsa_key /etc/ssh/ssh_host_ed25519_key /etc/ssh/ssh_host_rsa_keyExpected output:
Enforcing root LK 2026-09-28 0 99999 7 -1 (Password locked.) maxauthtries 4 clientaliveinterval 300 permitrootlogin no pubkeyauthentication yes passwordauthentication no banner /etc/issue.net authorizedkeyscommand none Authorized users only. All activity may be monitored and reported. EC2 Instance Connect: not installed -rw-------. 1 root ssh_keys 537 Oct 19 23:53 /etc/ssh/ssh_host_ecdsa_key -rw-------. 1 root ssh_keys 432 Oct 19 23:53 /etc/ssh/ssh_host_ed25519_key -rw-------. 1 root ssh_keys 2622 Oct 19 23:53 /etc/ssh/ssh_host_rsa_keyEnforcingmeans SELinux is on and enforcing the targeted policy. Keep it on. If your own software is denied, checksudo ausearch -m avc -ts recentrather than disabling SELinux.LKmeans the root account is locked.maxauthtries 4andclientaliveinterval 300come from the CIS profile. SSH allows four authentication attempts per connection and checks idle sessions every five minutes.authorizedkeyscommand nonemeans SSH reads keys only from each user'sauthorized_keysfile.- The banner text is shown before login.
- The SSH host keys are created on your instance's first boot and are readable by root only (
-rw-------). AlmaLinux creates them group-readable byssh_keys. A small boot service,sac-sshd-hostkey-perms.service, tightens them to0600before the SSH server starts, which is what the CIS rule for host key permissions checks.
EC2 Instance Connect is not installed. The AlmaLinux 8 base image carried it as an unsigned package from outside the AlmaLinux repositories, so dnf could never update it. It also added a second way to authorize SSH keys, through the EC2 Instance Connect API. It is removed so that your key pair is the only SSH credential. Use Session Manager (Step 2) for browser-based access.
EC2 Serial Console and recovery. No account on this image has a password, so the serial console cannot log in until you set one. If you want serial console access, set a password for your own user on your running instance. The password is yours and is not on the image:
sudo passwd ec2-userDisk size, swap and file integrity
Check the root filesystem, the cloud-init disk growth, swap and the AIDE schedule:
df -hT /
sudo grep -E 'cc_growpart.*(resized|NOCHANGE)' /var/log/cloud-init.log | tail -1 swapon --noheadings --show | wc -l sudo grep -h aide /etc/crontabExpected output with the default 10 GiB root volume (on a larger volume, Size is larger and the cloud-init line says resized):
Filesystem Type Size Used Avail Use% Mounted on /dev/nvme0n1p4 xfs 8.8G 3.3G 5.6G 37% / 2026-10-19 23:53:55,341 - cc_growpart.py[DEBUG]: '/' NOCHANGE: no change necessary (/dev/nvme0n1, 4) 0 05 4 * * * root /usr/sbin/aide --check- Disk layout. The instance boots with UEFI. The root filesystem is XFS on partition 4 of the root volume.
/boot(XFS) and/boot/efiare separate small partitions. - Disk use. About 1.6 GB of the used space is the
linux-firmwarebundle (Step 4). Thednfmetadata cache that the refresh in Step 10 downloads adds a little over 200 MB, andsudo dnf clean allremoves it. Choose a larger root volume at launch if you need room for your own software and data. - Disk growth. cloud-init grows the root partition and filesystem to the volume size on first boot. To grow later, increase the EBS volume size in the console or with
aws ec2 modify-volume, then runsudo growpart /dev/nvme0n1 4 && sudo xfs_growfs /(or reboot). - Swap. The image has no swap. Add a swap file yourself if your workload needs one.
- AIDE. The file integrity database is built from the image's own files, and the CIS profile schedules
aide --checkdaily at 04:05 from/etc/crontab.
Install software and add users
The instance uses the standard AlmaLinux 8 repositories (BaseOS, AppStream and Extras):
sudo dnf -q list --available nginxExpected output (the version changes over time):
Available Packages nginx.x86_64 1:1.14.1-9.module_el8.10.0+4171+d7eec01b.alma.1 appstreamAlmaLinux 8 ships several versions of some software as module streams. The default nginx stream is 1.14. sudo dnf module list nginx lists the newer streams (up to 1.24), and sudo dnf -y module enable nginx:1.24 selects one before you install.
Install and start software in the usual way, for example sudo dnf -y install nginx then sudo systemctl enable --now nginx. Then open its port in the security group and firewalld (Step 8). The AWS CLI is not on the image. Install the current version from AWS (the AWS CLI install guide) if you need it.
To add another administrator, create the account, add it to the wheel group and give it an SSH key:
sudo useradd -m -G wheel alice
sudo install -d -m 700 -o alice -g alice /home/alice/.ssh echo "ssh-ed25519 AAAA... alice@laptop" | sudo tee /home/alice/.ssh/authorized_keys
sudo chown alice:alice /home/alice/.ssh/authorized_keys && sudo chmod 600 /home/alice/.ssh/authorized_keys
sudo restorecon -R /home/alice/.sshBecause SSH is key-only, a new account needs its key in authorized_keys. restorecon gives the file the SELinux label that sshd expects.
The new account has no password, so sudo cannot authenticate it until you give it one with sudo passwd alice. SSH stays key-only, and sudo uses the password. Only ec2-user, created by cloud-init, has password-free sudo.
Common use cases
- Software certified or packaged for RHEL 8-compatible systems that is not yet supported on a 9 or 10 release
- A base for workloads that must show CIS Level 1 alignment on an enterprise Linux 8, with the evaluation report already on the machine
- Migrating CentOS 8 or other EL8 workloads to a supported distribution, with the standard package set and
tunedas AlmaLinux ships them - Fleets managed through Systems Manager, with IMDSv2 required from the first boot
- A starting point for your own golden image: add your software, re-run Step 6, and keep the report with your build
Troubleshooting
SSH says "Too many authentication failures"
The SSH server allows four authentication attempts per connection. If your SSH agent holds several keys, it can use them all up before it offers the right one. Tell SSH to offer only the key you name:
ssh -o IdentitiesOnly=yes -i ~/.ssh/my-key-pair.pem ec2-user@<public-ip>Cannot connect via SSH
- Check that the instance is running and has passed its status checks.
- Check that the security group allows TCP 22 from your current public address.
- Use the user name
ec2-userand the key pair chosen at launch. Password login is disabled, so a wrong key never falls back to a password prompt. - If you changed firewalld, make sure the
sshservice is still allowed. Session Manager (Step 2) still works if SSH is blocked, provided the instance has a Systems Manager instance profile.
My service is running but not reachable
Allow the port in both the security group and firewalld (Step 8). sudo firewall-cmd --list-all shows the firewalld rules, and sudo ss -tlnp shows whether the service listens on all addresses or only on loopback.
If the service runs on a non-standard port, SELinux may also need to allow it. Install the SELinux management tools with sudo dnf -y install policycoreutils-python-utils. Then allow the port, for example sudo semanage port -a -t http_port_t -p tcp 8080 for a web server on 8080.
A tool that uses instance metadata fails
The image requires IMDSv2. Old scripts that call http://169.254.169.254/ without a token get HTTP 401. Update them to request a token first (Step 7), or use the AWS CLI or a current SDK.
Package manager issues
Refresh the metadata first:
sudo dnf -q makecache --refresh && echo "repository metadata refreshed"If the repositories are unreachable, check that the instance has outbound internet access, through a public IP or a NAT gateway, and that DNS resolves:
getent hosts repo.almalinux.orgImportant notes
AlmaLinux is free and open source software. It is a distribution of thousands of packages, each under its own licence (GPL, LGPL, MIT, BSD, Apache 2.0 and others). rpm -qi <package> shows each package's licence. No subscription or licence key is needed to run this image. The compliance tooling is OpenSCAP (LGPL 2.1 or later) and SCAP Security Guide content (BSD 3-Clause, licence text in /usr/share/doc/sac/scap-security-guide-LICENSE.txt).
AlmaLinux 8 receives security updates from the AlmaLinux OS Foundation until 2029. 8.10 is its last minor release, so this version stays on 8.10 and takes updates through dnf. For a longer support window, the listing also offers AlmaLinux 9 and 10.
The CIS Level 1 Server profile used here is the OpenSCAP profile published in SCAP Security Guide. These images are not CIS Hardened Images and are not certified by the Center for Internet Security. A pass rate measures this image as built. Your own changes affect it, which is why you can re-run the evaluation (Step 6).
AlmaLinux is a trademark of the AlmaLinux OS Foundation. Red Hat Enterprise Linux is a trademark of Red Hat, Inc. CIS is a trademark of the Center for Internet Security. These names are used only to identify the software, its compatibility and the profile. SecureAnyCloud is not affiliated with or endorsed by the AlmaLinux OS Foundation, Red Hat or the Center for Internet Security.
Support
For help with this image, contact SecureAnyCloud support:
- Website: secureanycloud.com
- User guides: secureanycloud.com/guides
- AlmaLinux on AWS hub: secureanycloud.com/guides/almalinux-aws
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