Chapter 2. Threat and Vulnerability Management

Red Hat Ceph Storage (RHCS) is typically deployed in conjunction with cloud computing solutions, so it can be helpful to think about an Red Hat Ceph Storage deployment abstractly as one of many series of components in a larger deployment. These deployments typically have shared security concerns, which this guide refers to as Security Zones. Threat actors and vectors are classified based on their motivation and access to resources. The intention is to provide you with a sense of the security concerns for each zone, depending on your objectives.

2.1. Threat Actors

A threat actor is an abstract way to refer to a class of adversary that you might attempt to defend against. The more capable the actor, the more rigorous the security controls that are required for successful attack mitigation and prevention. Security is a matter of balancing convenience, defense, and cost, based on requirements. In some cases it will not be possible to secure a Red Hat Ceph Storage deployment against all of the threat actors described here. When deploying Red Hat Ceph Storage, you must decide where the balance lies for your deployment and usage.

As part of your risk assessment, you must also consider the type of data you store and any accessible resources, as this will also influence certain actors. However, even if your data is not appealing to threat actors, they could simply be attracted to your computing resources.

  • Nation-State Actors: This is the most capable adversary. Nation-state actors can bring tremendous resources against a target. They have capabilities beyond that of any other actor. It is very difficult to defend against these actors without incredibly stringent controls in place, both human and technical.
  • Serious Organized Crime: This class describes highly capable and financially driven groups of attackers. They are able to fund in-house exploit development and target research. In recent years the rise of organizations such as the Russian Business Network, a massive cyber-criminal enterprise, has demonstrated how cyber attacks have become a commodity. Industrial espionage falls within the serious organized crime group.
  • Highly Capable Groups: This refers to ‘Hacktivist’ type organizations who are not typically commercially funded but can pose a serious threat to service providers and cloud operators.
  • Motivated Individuals Acting Alone: These attackers come in many guises, such as rogue or malicious employees, disaffected customers, or small-scale industrial espionage.
  • Script Kiddies: These attackers don’t target a specific organization, but run automated vulnerability scanning and exploitation. They are often only a nuisance, however compromise by one of these actors is a major risk to an organization’s reputation.

The following practices can help mitigate some of the risks identified above:

  • Security Updates: You must consider the end-to-end security posture of your underlying physical infrastructure, including networking, storage, and server hardware. These systems will require their own security hardening practices. For your Red Hat Ceph Storage deployment, you should have a plan to regularly test and deploy security updates.
  • Access Management: Access management includes authentication, authorization and accounting. Authentication is the process of verifying the user identity. Authorization is the process of granting permissions to an authenticated user. Accounting is the process of tracking which user performed an action. When granting system access to users, apply the principle of least privilege, and only grant users the granular system privileges they actually need. This approach can also help mitigate the risks of both malicious actors and typographical errors from system administrators.
  • Manage Insiders: You can help mitigate the threat of malicious insiders by applying careful assignment of role-based access control (minimum required access), using encryption on internal interfaces, and using authentication/authorization security (such as centralized identity management). You can also consider additional non-technical options, such as separation of duties and irregular job role rotation.

2.2. Security Zones

A security zone comprises users, applications, servers or networks that share common trust requirements and expectations within a system. Typically they share the same authentication and authorization requirements and users. Although you may refine these zone definitions further, this guide refers to four distinct security zones, three of which form the bare minimum that is required to deploy a security-hardened Red Hat Ceph Storage cluster. These security zones are listed below from least to most trusted:

  • Public Security Zone: The public security zone is an entirely untrusted area of the cloud infrastructure. It can refer to the Internet as a whole or simply to networks that are external to your Red Hat OpenStack deployment over which you have no authority. Any data with confidentiality or integrity requirements that traverse this zone should be protected using compensating controls such as encryption. The public security zone SHOULD NOT be confused with the Ceph Storage Cluster’s front- or client-side network, which is referred to as the public_network in RHCS and is usually NOT part of the public security zone or the Ceph client security zone.
  • Ceph Client Security Zone: With RHCS, the Ceph client security zone refers to networks accessing Ceph clients such as Ceph Object Gateway, Ceph Block Device, Ceph Filesystem, or librados. The Ceph client security zone is typically behind a firewall separating itself from the public security zone. However, Ceph clients are not always protected from the public security zone. It is possible to expose the Ceph Object Gateway’s S3 and Swift APIs in the public security zone.
  • Storage Access Security Zone: The storage access security zone refers to internal networks providing Ceph clients with access to the Ceph Storage Cluster. We use the phrase 'storage access security zone' so that this document is consistent with the terminology used in the OpenStack Platform Security and Hardening Guide. The storage access security zone includes the Ceph Storage Cluster’s front- or client-side network, which is referred to as the public_network in RHCS.
  • Ceph Cluster Security Zone: The Ceph cluster security zone refers the internal networks providing the Ceph Storage Cluster’s OSD daemons with network communications for replication, heartbeating, backfilling, and recovery. The Ceph cluster security zone includes the Ceph Storage Cluster’s backside network, which is referred to as the cluster_network in RHCS.

These security zones can be mapped separately, or combined to represent the majority of the possible areas of trust within a given RHCS deployment. Security zones should be mapped out against your specific RHCS deployment topology. The zones and their trust requirements will vary depending upon whether Red Hat Ceph Storage is operating in a standalone capacity or is serving a public, private, or hybrid cloud.

For a visual representation of these security zones, see Security Optimized Architecture.

Additional Resources

  • See the Network Communications section in the Red Hat Ceph Storage Data Security and Hardenng Guide for more details.

2.3. Connecting Security Zones

Any component that spans across multiple security zones with different trust levels or authentication requirements must be carefully configured. These connections are often the weak points in network architecture, and should always be configured to meet the security requirements of the highest trust level of any of the zones being connected. In many cases the security controls of the connected zones should be a primary concern due to the likelihood of attack. The points where zones meet do present an opportunity for attackers to migrate or target their attack to more sensitive parts of the deployment.

In some cases, Red Hat Ceph Storage administrators might want to consider securing integration points at a higher standard than any of the zones in which the integration point resides. For example, the Ceph Cluster Security Zone can be isolated from other security zones easily, because there is no reason for it to connect to other security zones. By contrast, the Storage Access Security Zone must provide access to port 6789 on Ceph monitor nodes, and ports 6800-7300 on Ceph OSD nodes. However, port 3000 should be exclusive to the Storage Access Security Zone, because it provides access to Ceph Graphana monitoring information that should be exposed to Ceph administrators only. A Ceph Object Gateway in the Ceph Client Security Zone will need to access the Ceph Cluster Security Zone’s monitors (port 6789) and OSDs (ports 6800-7300), and may expose its S3 and Swift APIs to the Public Security Zone such as over HTTP port 80 or HTTPS port 443; yet, it may still need to restrict access to the admin API.

The design of Red Hat Ceph Storage is such that separation of security zones is difficult. Because core services will usually span at least two zones, special consideration must be given when applying security controls to them.

2.4. Security-Optimized Architecture

A Red Hat Ceph Storage cluster’s daemons typically run on nodes that are subnet isolated and behind a firewall, which makes it relatively simple to secure an RHCS cluster.

By contrast, Red Hat Ceph Storage clients such as Ceph Block Device (rbd), Ceph Filesystem (cephfs) and Ceph Object Gateway (rgw) access the RHCS storage cluster, but expose their services to other cloud computing platforms.

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