Monday, March 25, 2019

Cloud computing threats, vulnerabilities and risks

Cloud computing threats, vulnerabilities and risks
As pointed out in a previous article on cloud computing project management, one thing that has changed a lot with the rise of cloud usage is security.

Your cloud computing environment experiences at a high level the same threats as your traditional data center environment. Your threat picture is more or less the same.

Both environments run software, software has vulnerabilities, and adversaries try to exploit those vulnerabilities.

But unlike your systems in a traditional data center, in cloud computing, responsibility for mitigating the risks that result from these software vulnerabilities is shared between the provider and you, the customer.

For that reason, you must understand the division of responsibilities and trust that the provider will hold up their end of the bargain.

This article discusses the 12 biggest threats and vulnerabilities for a cloud computing environment. It splits these into a set of cloud-unique and a set of shared cloud/on-premises vulnerabilities and threats. But before we start, we have to clarify some definitions, because some of the most commonly mixed-up security terms are actually threat, vulnerability, and risk.

Assets, Threats, Vulnerabilities, and Risk

While it might be unreasonable to expect those outside the security industry to understand the differences, more often than not, many in the business use terms such as “asset,” “threat,” “vulnerability,” and “risk” incorrectly or interchangeably. So maybe providing some definitions for those terms will help to make the rest of the article clearer.

Asset – People, property, and information. People may include employees and customers along with other invited persons such as contractors or guests. Property assets consist of both tangible and intangible items that can be assigned a value. Intangible assets include reputation and proprietary information. Information may include databases, software code, critical company records, and many other intangible items. An asset is what we’re trying to protect.

Threat – Anything that can exploit a vulnerability, intentionally or accidentally, and obtain, damage, or destroy an asset. A threat is what we’re trying to protect against.

Vulnerability – Weaknesses or gaps in a security program that can be exploited by threats to gain unauthorized access to an asset. A vulnerability is a weakness or gap in our protection efforts.

Risk – The potential for loss, damage or destruction of an asset as a result of a threat exploiting a vulnerability. Why is it important to understand the difference between these terms? If you don’t understand the difference, you’ll never understand the true risk to assets. You see, when conducting a risk assessment, the formula used to determine risk is:

Asset + Threat + Vulnerability = Risk

Cloud characteristics

While we're defining terms, let’s define cloud computing as well. The most meaningful way to do so in a security context is, in my opinion, by the five cloud computing characteristics published by the National Institute of Standards and Technology (NIST). They are:

1) On-demand self-service: A customer can unilaterally provision computing capabilities, such as server time and network storage, as needed automatically without requiring human interaction with each service provider.

2) Broad network access: Capabilities are available over the network and accessed through standard mechanisms that promote use by heterogeneous thin or thick client platforms (e.g., mobile phones, tablets, laptops and workstations).

3) Resource pooling: The provider's computing resources are pooled to serve multiple consumers using a multi-tenant model, with different physical and virtual resources dynamically assigned and reassigned according to customer demand. There is a sense of location independence in that the customer generally has no control or knowledge over the exact location of the provided resources but may be able to specify location at a higher level of abstraction (e.g., country, state or datacenter). Examples of resources include storage, processing, memory and network bandwidth.

4) Rapid elasticity: Capabilities can be elastically provisioned and released, in some cases automatically, to scale rapidly outward and inward commensurate with demand. To the customer, the capabilities available for provisioning often appear to be unlimited and can be appropriated in any quantity at any time.

5) Measured service: Cloud systems automatically control and optimize resource use by leveraging a metering capability at some level of abstraction appropriate to the type of service (e.g., storage, processing, bandwidth and active user accounts). Resource usage can be monitored, controlled and reported, providing transparency for the provider and customer.

Cloud-specific threats and vulnerabilities

The following vulnerabilities are a result of a cloud service provider’s implementation of the five cloud computing characteristics described above. These vulnerabilities do not exist in classic IT data centers.

#1 Reduced visibility and control

When transitioning your assets/operations to the cloud, your organization loses some visibility and control over those assets/operations. When using external cloud services, the responsibility for some of the policies and infrastructure moves to the provider.

The actual shift of responsibility depends on the cloud service model(s) used, leading to a paradigm shift for customers in relation to security monitoring and logging. Your organization needs to perform monitoring and analysis of information about applications, services, data, and users, without using network-based monitoring and logging, which is available for your on-premises IT.

#2 On-demand self-service

Providers make it very easy to provision new services. The on-demand self-service provisioning features of the cloud enables your organization's employees to provision additional services from the provider without IT consent. This practice of using software in an organization that is not supported by the organization's IT department is commonly referred to as shadow IT.

Due to the lower costs and ease of implementing platform as a service (PaaS) and software as a service (SaaS) products, the probability of unauthorized use of cloud services increases. Services provisioned or used without IT's knowledge present risks to an organization. The use of unauthorized cloud services could result in an increase in malware infections or data exfiltration since your organization is unable to protect resources it does not know about. The use of unauthorized cloud services also decreases your organization's visibility and control of network and data.

#3 Internet-accessible management APIs 

Providers expose a set of application programming interfaces (APIs) that customers use to manage and interact with cloud services (also known as the management plane). Organizations use these APIs to provision, manage, orchestrate, and monitor their assets and users. These APIs can contain the same software vulnerabilities as an API for an operating system, library, etc. Unlike management APIs for on-premises computing, provider APIs are accessible via the Internet, exposing them more broadly to potential exploitation.

Threat actors look for vulnerabilities in management APIs. If discovered, these vulnerabilities can be targeted for successful attacks, and an organization’s cloud assets can be compromised. From there, attackers can use organization assets to perpetrate further attacks against other customers of the provider.

#4 Multi-tenancy 

Exploitation of system and software vulnerabilities within a provider's infrastructure, platforms, or applications that support multi-tenancy can lead to a failure to maintain separation among tenants. This failure can be used by an attacker to gain access from one organization's resource to another user's or organization's assets or data. Multi-tenancy increases the attack surface, leading to an increased chance of data leakage if the separation controls fail.

This attack can be accomplished by exploiting vulnerabilities in the provider's applications, hypervisor, or hardware, subverting logical isolation controls or attacks on the provider's management API.

No reports of an attack based on logical separation failure have been identified; however, proof-of-concept exploits have been demonstrated.

#5 Data deletion 

Threats associated with data deletion exist because the consumer has reduced visibility into where their data is physically stored in the cloud and a reduced ability to verify the secure deletion of their data. This risk is concerning because the data is spread over a number of different storage devices within the provider's infrastructure in a multi-tenancy environment. In addition, deletion procedures may differ from provider to provider. Organizations may not be able to verify that their data was securely deleted and that remnants of the data are not available to attackers. This threat increases as a customer uses more provider services.

Cloud and on-premises threats and vulnerabilities

The following are threats and vulnerabilities that apply to both cloud and on-premises IT data centers that organizations need to address.

#6 Credentials are stolen

If an attacker gains access to one of your user's cloud credentials, the attacker can have access to the provider's services to provision additional resources (if credentials allowed access to provisioning), as well as target your organization's assets. The attacker could leverage cloud computing resources to target your organization's administrative users, other organizations using the same provider, or the provider's administrators. An attacker who gains access to a provider administrator's cloud credentials may be able to use those credentials to access the customers’ systems and data.

Administrator roles vary between a provider and an organization. The provider administrator has access to the provider network, systems, and applications (depending on the service) of the provider's infrastructure, whereas the customer's administrators have access only to the organization's cloud implementations. In essence, the provider administrator has administration rights over more than one customer and supports multiple services.

#7 Vendor lock-in 

Vendor lock-in becomes an issue when your organization considers moving its assets/operations from one provider to another. Your organization will probably discover that the cost/effort/schedule time necessary for the move is much higher than initially considered due to factors such as non-standard data formats, non-standard APIs, and reliance on one provider's proprietary tools and unique APIs.

This issue increases in service models where the provider takes more responsibility. As a customer uses more features, services, or APIs, the exposure to a provider's unique implementations increases. These unique implementations require changes when a capability is moved to a different provider. If a selected provider goes out of business, it becomes a major problem since data can be lost or may not be able to be transferred to another provider in a timely manner.

#8 Increased complexity 

Migrating to the cloud can introduce complexity into IT operations. Managing, integrating, and operating in the cloud may require that the organization's existing IT staff learn a new model. IT staff must have the capacity and skill level to manage, integrate, and maintain the migration of assets and data to the cloud in addition to their current responsibilities for on-premises IT.

Key management and encryption services become more complex in the cloud. The services, techniques, and tools available to log and monitor cloud services typically vary across providers, further increasing complexity. There may also be emergent threats/risks in hybrid cloud implementations due to technology, policies, and implementation methods, which add complexity.

This added complexity leads to an increased potential for security gaps in an agency's cloud and on-premises implementations.

#9 Insider abuse 

Insiders, such as staff and administrators for both organizations and providers, who abuse their authorized access to the organization's or provider's networks, systems, and data are uniquely positioned to cause damage or exfiltrate information.

The impact is most likely worse when using infrastructure as a service (IaaS) due to an insider's ability to provision resources or perform nefarious activities that require forensics for detection. These forensic capabilities may not be available with cloud resources.

#10 Lost data 

Data stored in the cloud can be lost for reasons other than malicious attacks. Accidental deletion of data by the cloud service provider or a physical catastrophe, such as a fire or earthquake, can lead to the permanent loss of customer data. The burden of avoiding data loss does not fall solely on the provider's shoulders. If a customer encrypts its data before uploading it to the cloud but loses the encryption key, the data will be lost. In addition, inadequate understanding of a provider's storage model may result in data loss. Organizations must consider data recovery and be prepared for the possibility of their provider being acquired, changing service offerings, or going bankrupt.

This threat increases as an organization uses more provider services. Recovering data from a provider may be easier than recovering it at an agency because a service level agreement (SLA) designates availability/uptime percentages. These percentages should be investigated when your organization selects a provider.

#11 Provider supply chain 

If your provider outsources parts of its infrastructure, operations, or maintenance, these third parties may not satisfy/support the requirements that the provider is contracted to provide with for organization. Your organization needs to evaluate how the provider enforces compliance and check to see if the provider flows its own requirements down to third parties. If the requirements are not being levied on the supply chain, then the threat to your organization increases.

This threat increases as your organization uses more provider services and is dependent on individual providers and their supply chain policies.

#12 Insufficient due diligence 

Organizations migrating to the cloud often perform insufficient due diligence. They move data to the cloud without understanding the full scope of doing so, the security measures used by the provider, and their own responsibility to provide security measures. They make decisions to use cloud services without fully understanding how those services must be secured.

Conclusion

Although the level of threat in a cloud computing environment is similar to that of a traditional data center, there is a key difference in who is responsible for mitigating the risk. It is important to remember that cloud service providers use a shared responsibility model for security. Your provider accepts responsibility for some aspects of security. Other aspects of security are shared between your provider and you, the customer. And some aspects of security remain the sole responsibility of the consumer. Successful cloud security depends on both parties knowing and meeting all their responsibilities effectively. The failure of organizations to understand or meet their responsibilities is a leading cause of security incidents in cloud computing environments.
Posted on Monday, March 25, 2019 by Henrico Dolfing

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