Service Account 101: the Power of M2M with Security in Mind

Service accounts are an essential component of many IT environments, allowing applications and services to access various resources without requiring user intervention. However, if not managed properly, service accounts can pose significant security risks to an organization.

In this article, we will explore the benefits of using service accounts, as well as the limitations and security risks associated with them. We will also discuss some best practices for effectively managing service accounts, in regard to a security and governance point of view.

Service account vs user account: what’s the difference?

In computing systems, user accounts and service accounts are both used for authentication and authorization. However, they have distinct purposes and characteristics that are important to understand.

A user account is created for individual users and holds the personal information associated with their identity: such information typically only makes sense when it is attributed to a real human being, who is identified by the account inside a digital environment.

Human-to-machine communication is typically facilitated by user accounts, which require human interaction to authenticate, such as entering a username and password. Users are typically granted access to computing resources based on their role and level of authorization.

On the other hand, a service account is an account used by an application or service to access computing resources: therefore, it lacks all those characteristics that could be associated by nature with a human user’s identity.

Service accounts are typically used for automated processes or to run specific services on behalf of multiple users. They are commonly employed in machine‑to‑machine (M2M) communication and follow specific authentication and authorization standards.

Service accounts are particularly handy in cloud computing environments, where applications and services need to interact with resources across different servers and networks. The registration and login process of a service account can be managed by dedicated services, such as the Client Credentials service we talked about in a previous article.

How can you use a service account? Some examples

One of the possible uses of a service account is to access resources, such as files, databases, or APIs that are not available to regular user accounts. In a cloud environment, a service account can manage resources such as virtual machines, containers, or infrastructure components. For instance, it could be used to monitor and log Kubernetes resources, such as Pods, Deployments, and Services. Once authorized, the service account could use specific tools to collect and analyze data for auditing and troubleshooting purposes.

Another common scenario is having a service account tasked with executing processes or scripts that automate activities or interact with other systems. For instance, you can grant a service account permission to make automatic code deploys, improving the speed of the software development process.

A service account can also be useful to securely store and manage the credentials used to authenticate with other systems or services.

Advantages of service accounts

Before we delve into the advantages of service accounts, it is important to note that many of the benefits we will talk about in this section can easily become issues if we ignore the recommended security and governance best practices that will be covered later in this article.

One of the greatest advantages of service accounts is automation: they are designed to access resources and perform operations without the need for human intervention. This is useful for applications that require continuous monitoring, reporting, or data processing.

Service accounts are also potentially great for security. Using service accounts promotes the separation of roles and responsibilities, which reduces the risk of credential misuse or theft. In fact, service accounts are - or should be - typically granted only those permissions necessary to achieve a specific purpose. Limiting permissions and only granting access to the resources explicitly needed by the application or service can reduce the risk of privilege escalation.
In contrast, user accounts typically have higher privileges than necessary to perform their assigned tasks, which increases the risk of unwanted actions or data breaches. Moreover, service accounts can also help eliminate human error during login, password reset, and password change, ensuring that every process is carried out consistently.

Another great perk of service accounts is that they provide an opportunity for efficient governance: firstly, they can be created and deleted as needed, making them highly scalable.

To achieve this, however, it is fundamental to establish a rigorous management system for these accounts, in order to keep track of their existence, capabilities, and purpose from the moment they are created until the moment they are no longer useful and can be deleted.
If managed properly, this is a great advantage over traditional user accounts, which can be time‑consuming and challenging to manage at scale.

Moreover, service accounts are useful when differentiating access to multiple environments. Multiple accounts can be created for different environments, such as development, testing, or production, making it easier to manage access control between environments.

Finally, service accounts enable more straightforward auditing, as they are not tied to individual users who may come and go. Instead, they are linked to specific applications or systems, making it easier to track and review activity logged by those accounts.
This is another situation in which it is crucial to have a strong governance structure for service accounts, without which it would be impossible to trace back to their specific function inside an organization’s digital environment.

How can a service account become a security issue?

Although service accounts are a useful tool, there are several ways in which a service account can be abused that must be taken into account in order to prevent them.

One of the main risks of using service accounts is privilege escalation, meaning that a bad actor might gain access to resources they otherwise wouldn't have access to by impersonating the service account. Impersonation happens when an identity, which can be a user or another service account, manages to authenticate as the service account and is therefore granted elevated access to certain resources by temporarily gaining the privileges of the impersonated service account.

Impersonation can also be used as a form of spoofing, to obscure the identity of the bad actor, and if a monitoring system has not been properly set up to check for service account activity, it might not be possible to trace the malicious actions back to their source.

In fact, service accounts can create blind spots in audit logs or security analytics tools, making it difficult to identify who has used the account. Therefore, they can create ambiguity and a lack of accountability around who is responsible for the activities performed by them.

Securing your service accounts: best practices

Service accounts play a critical role in the secure management of IT environments, and it is essential to safeguard them against potential security threats.

The dual nature of service accounts

When it comes to secure management of service accounts, it is essential to acknowledge their two‑fold nature.

First of all, a service account is an identity that can be authorized to access resources. Therefore it is crucial to restrict its privileges, to minimize the potential harm that can be inflicted by it in the case it becomes compromised.

For instance, if a bad actor has already gained a foothold in an environment, it might not have sufficient permissions to directly access certain resources in that environment. However, if the malicious identity finds a way to impersonate an existing service account with higher privileges, it might gain the capability to further extend its own privileges and do more damage.

From the previous example, we can notice that a service account is also a resource, so it must be safeguarded against any unauthorized access to avoid any potential compromises, just like any other critical resource.

Managing service account credentials

The first way to protect service accounts is to properly generate and store their credentials. In the OAuth 2.0 standard, there are two methods available for authenticating a service account:

• Client Secret Basic: it requires an identifier for the service account, called the client id, and a client secret, so it is very similar to the concept of authenticating with username and password. This method is simple to implement and provides a basic level of security.
• Private Key JWT: it uses asymmetric encryption keys for authentication. This method is to be preferred since it provides a higher level of security: the private key is never transmitted over the network nor shared with the server, so it is better protected from any attacks.

Knowing the private key of a service account’s key pair is similar to knowing a user’s password, therefore it is important to store it in a safe place where it can not be subject to leakage. A poorly protected service account key could be used by a malicious identity to perform undesired operations in disguise.

One good security measure is to avoid uploading service account keys to cloud storage systems or source code repositories, as well as trying not to share them between users through e-mails or chats where they could be easily accessed. It is also recommended to limit the proliferation of service account keys, while also monitoring the presence of unused ones and using expiry times to let them expire automatically.

More generally, you could ensure that access to service accounts is restricted only to authorized users or systems by implementing IP restrictions or role-based access controls.

Limiting service account privileges and range of action

In general, when you decide to set up a service account, remember to implement least privilege access control by granting it the least privileges required to perform its tasks and limiting its access to critical resources. Also, try to follow the principle of separation of duties: create separate service accounts for different applications in order to limit their range of action to the specific purpose of the service.

Once you have some service accounts in your environment, you should set up a proper monitoring system to check for any signs of suspicious activity regularly.

It is also a good practice to keep an inventory of all service accounts and their purposes, in order to avoid leaving any unused service accounts around. For example, legacy accounts that have been replaced by newer systems, or accounts that were created for temporary activities and have not been removed after fulfilling their purpose.

Another useful thing to do is regularly review service account permissions, in order to determine if they are still appropriate or should be redefined to stay in line with current business requirements and changing security risks.

Last but not least, to minimize security risks and maintain a secure environment, always avoid using a service account for human login purposes. When human users are granted access using service accounts, it becomes harder to track and audit the actions performed, since it is difficult to distinguish between automated and manual activities. This could make it difficult to investigate security incidents and identify the root cause of security issues. Moreover, using service accounts for human login may result in credentials being stored in insecure ways, which could be compromised by attackers.

Tips for efficient identity management

There are some useful factors to take into account when determining the appropriate use of service accounts for the benefit of an organization.

First of all, consider the purpose of the account. If the account will be used by an application or system process, it's best to use a service account. If the account is for a human user, a normal user account is appropriate. Identify the services or applications that might need to automate tasks and integrate systems without human intervention: in those cases, creating a dedicated service account might be the appropriate solution.

Then, think about the scope of the account. Service accounts are often used for specific processes, while normal user accounts are used for general computing tasks.

Also, consider the level of security needed for the account. Service accounts typically have more access and privileges than normal user accounts, so it's important to ensure the account is secure and not easily compromised.

With regards to governance, consider the ease of user account management. Service accounts can often be managed centrally, while normal user accounts may require more individual attention.

Finally, be aware of any compliance requirements that may dictate the use of a specific type of account. Companies may create service accounts dedicated to handling critical operations involving personal data, like credit cards or healthcare information, to comply with regulations such as the GDPR, which sets rules for how organizations should process and protect the personal data of EU citizens.

The Bottom Line

In conclusion, service accounts can provide a convenient and secure way to manage access to cloud resources, but they also come with their own set of limitations and risks.

By following best practices you can minimize the potential for security breaches and ensure that your service accounts are being used in a responsible and secure manner. With the right approach, service accounts can be a valuable tool for any organization looking to manage access to their cloud resources more efficiently.

As always, it's important to stay vigilant and up‑to‑date on the latest security threats and best practices. By staying informed and taking a proactive approach to managing your service accounts, you can help ensure the long‑term security and success of your cloud‑based infrastructure.

Starting from the latest major release, Mia‑Platform Console features Service accounts management. Please refer to the documentation for further details on the feature. You can also learn more about Mia‑Platform v11 and all its new functionality on this page.

This article was written by Giovanna Monti, Full Stack Developer Specialist at Mia‑Platform.