Critical Security Hardening Issues In Ansible Infrastructure

Hey guys! Today, we're diving deep into some critical security issues identified in Ansible infrastructure. It’s super important to address these vulnerabilities to keep our systems safe and sound. This article will walk you through the issues, the risks involved, and how to fix them step-by-step. Let's get started!

Understanding the Security Risks

Before we jump into the nitty-gritty, let’s quickly talk about why these security measures matter. Security misconfigurations can leave our systems vulnerable to attacks, data breaches, and unauthorized access. Think of it like leaving your front door wide open – not a great idea, right? So, let’s make sure we lock things down properly.

A. Disabled Host Key Checking in ansible.cfg

Okay, so first up, we've got disabled host key checking in the ansible.cfg file. This is a big one. When host_key_checking is set to False, it's like saying, "Hey, I trust every server I connect to, no questions asked!" Sounds risky, right? It is!

Current Configuration (The Problem):

[defaults]
host_key_checking = False  # ⚠️ SECURITY RISK

Risk: Man-in-the-Middle Attacks

The main risk here is Man-in-the-Middle (MITM) attacks. Imagine someone intercepts your connection and pretends to be the server you're trying to reach. Without host key checking, you wouldn't even know! They could steal your data, inject malicious code, or wreak all sorts of havoc. We definitely don't want that.

The Solution: Enable Host Key Checking

The fix is pretty straightforward. We need to enable host key checking and maintain a known_hosts file. This file acts like a whitelist of trusted servers. When you connect to a server, Ansible checks its key against the one in known_hosts. If they match, you're good to go. If not, Ansible raises a red flag.

Fixed Configuration (The Solution):

[defaults]
host_key_checking = True

By setting host_key_checking to True, we're adding a crucial layer of security. But remember, this is just the first step. We also need to make sure our known_hosts file is up-to-date and accurate. This involves adding the correct keys for all our servers. It might sound like a chore, but trust me, it’s worth it for the peace of mind.

B. PostgreSQL Listening on All Interfaces

Next up, let's talk about PostgreSQL. If your PostgreSQL database is listening on all interfaces, it's like shouting your secrets from the rooftops. Anyone on the network can try to connect, and that's a problem.

Current Configuration (The Problem):

postgresql_listen_address: "0.0.0.0"  # ⚠️ Too permissive

Here, 0.0.0.0 means PostgreSQL is listening on all available network interfaces. This is way too permissive and opens the door to potential attacks.

Risk: Database Exposed to the Entire Network

The big risk here is that your database is exposed to the entire network. Anyone who can reach your server can try to connect to your database. If they manage to get in, they could steal, modify, or delete your data. Not ideal, to say the least.

The Solution: Restrict PostgreSQL Listen Address

The fix is to restrict the listen address to only the necessary interfaces. A common approach is to listen on the loopback address (127.0.0.1) and the server’s specific IP address.

Fixed Configuration (The Solution):

postgresql_listen_address: "127.0.0.1,{{ ansible_default_ipv4.address }}"

By setting the postgresql_listen_address to 127.0.0.1 and the server's IP address, we're telling PostgreSQL to only accept connections from the local machine and the specified IP. This significantly reduces the attack surface.

Alternatively, you could implement firewall rules to restrict access to the PostgreSQL port (usually 5432). This adds another layer of security, making it even harder for unauthorized users to connect.

C. Redis Without Authentication

Last but definitely not least, we have Redis without authentication. Redis is an in-memory data structure store often used for caching and message brokering. If it's not properly secured, it can be a goldmine for attackers.

Current Configuration (The Problem):

# redis_requirepass: "CHANGEME_STRONG"  # ⚠️ Commented out!

Notice how redis_requirepass is commented out? That means Redis isn't requiring a password, which is a major security no-no.

Risk: Unprotected Redis Allows Unauthorized Access to Cache/Queues

Without authentication, anyone who can connect to your Redis instance can read, write, and delete data. They could steal sensitive information, inject malicious data, or even take control of your application. Imagine the chaos!

The Solution: Enable Redis Authentication

The fix involves setting a strong password for Redis and configuring it to require authentication. Here’s how to do it:

Step 1: Add a Password to vault.yml

First, we'll store our Redis password in a secure vault file. This is a good practice because it keeps sensitive information out of our main configuration files.

vault_redis_password: "<strong-random-password>"

Replace <strong-random-password> with a strong, randomly generated password. The longer and more complex, the better!

Step 2: Update group_vars/db_nodes.yml

Next, we'll reference the password from our vault in the group_vars/db_nodes.yml file.

redis_requirepass: "{{ vault_redis_password }}"

This tells Ansible to use the password we stored in the vault.

Step 3: Configure in Redis Role

Finally, we need to configure Redis to require a password. We'll do this by adding a task to our Redis Ansible role.

- name: Configure Redis authentication
  lineinfile:
    path: /etc/redis/redis.conf
    regexp: '^# requirepass'
    line: "requirepass {{ redis_requirepass }}"
  notify: restart redis

This task uses the lineinfile module to uncomment the requirepass directive in the Redis configuration file and set it to our password. The notify: restart redis part ensures that Redis is restarted after the configuration change.

By following these steps, we're adding a crucial layer of protection to our Redis instance. Now, only authorized users with the correct password can access our data.

Implementation Plan: Securing Our Infrastructure

Alright, now that we know the issues and the fixes, let's talk about how we're going to implement these changes. We'll break it down into phases to make it manageable and minimize disruption.

Phase 1: Immediate (1-2 Hours)

This phase is all about addressing the most critical issues right away.

1. Enable host_key_checking in ansible.cfg: This is a quick win that significantly improves security.
2. Remove StrictHostKeyChecking bypass: If we have any temporary workarounds in place, it’s time to remove them.
3. Add known_hosts entries for all servers: We need to make sure our known_hosts file is populated with the correct keys for all our servers.

Phase 2: Database Security (2-3 Hours)

In this phase, we'll focus on securing our databases.

1. Configure Redis authentication: We'll implement the steps outlined earlier to set a password for Redis.
2. Restrict PostgreSQL listen address: We'll update the postgresql_listen_address to limit connections.
3. Verify firewall rules: We'll double-check that our firewall rules are in place and are properly restricting access to our database ports.
4. Test service connectivity: After making these changes, we'll test to make sure our services can still connect to the databases.

Phase 3: Validation (1 Hour)

This phase is all about making sure our changes worked and didn't break anything.

1. Run playbooks with --check: We'll use Ansible's --check mode to simulate running our playbooks without actually making changes. This helps us catch any potential issues.
2. Verify all services are still accessible: We'll manually check that all our services are working as expected.
3. Document security improvements: We'll update our documentation to reflect the changes we've made.

Testing: Ensuring Our Security Measures Work

Testing is crucial to ensure our security measures are effective. Here are some commands we can use to verify our changes:

# Test connectivity with proper security
ansible all -i inventory/prod.ini -m ping

# Verify PostgreSQL access
ansible db_nodes -i inventory/prod.ini -m shell -a "psql -U postgres -c 'SELECT version();'"

# Verify Redis access (with password)
ansible db_nodes -i inventory/prod.ini -m shell -a "redis-cli -a {{ redis_requirepass }} ping"

These commands will help us confirm that our servers are reachable, PostgreSQL is accessible, and Redis requires authentication.

Acceptance Criteria: Knowing When We're Done

To make sure we've successfully addressed these security issues, we'll use the following acceptance criteria:

• [ ] host_key_checking enabled in ansible.cfg
• [ ] All hosts in known_hosts
• [ ] PostgreSQL listen address restricted
• [ ] Redis authentication configured
• [ ] All services accessible after changes
• [ ] Security audit passes

Once we've met all these criteria, we can be confident that our infrastructure is more secure.

Effort and Priority: Understanding the Scope

This is a 🔴 CRITICAL issue, and we estimate it will take ⏱️ 4-6 hours total to implement the fixes. Given the severity of the vulnerabilities, it's crucial to address these issues as soon as possible.

References: Diving Deeper

If you want to learn more about these security issues, here are some helpful references:

• Source: docs/deployment/ansible_infra_assessment.md #3 (replace with the actual link)
• Related: Issue #5 (StrictHostKeyChecking) (replace with the actual link)
• Related: Issue #18 (Redis IP hardcoding) (replace with the actual link)

Conclusion: Staying Secure

So, there you have it, guys! We've covered some critical security hardening issues in our Ansible infrastructure. By enabling host key checking, restricting PostgreSQL listen addresses, and configuring Redis authentication, we're taking big steps to protect our systems. Remember, security is an ongoing process, and it's essential to stay vigilant and proactive. Keep those doors locked, and your data safe!

For more in-depth information on security best practices, check out the OWASP (Open Web Application Security Project) website. They have tons of resources to help you stay secure.