Serverless’ Security Risks

 Serverless, which refers to serverless computing, is a type of cloud computing execution model in which it is the responsibility of the cloud provider to execute a piece of code through dynamic allocation of resources. In it, machine resources are allocated by the cloud provider, as per demand. Additionally, in it, servers are taken care of on customers’ behalf and the billing is based on the amount of resources that are used to run codes, which are run inside stateless containers. These are triggered by various events, such as database events, HTTP requests, monitoring alerts, queuing services, file uploads, cron jobs etc. The code that has to be executed, and which is sent to the cloud provider for this purpose, is usually a function. This is the reason why serverless is often referred to as FaaS ( Function as a Service). Resources are not held in volatile memory in serverless. When any app is not being used, it does not receive any computing resources.

The term “serverless” is a misnomer because servers are used in it for executing code for developers by cloud service providers. Serverless computing is useful as it simplifies the process involved in the deployment of code into production. The code that is deployed in serverless can be used with traditionally deployed code, which includes monoliths or microservices. It is also possible to write applications to be totally serverless, wherein no provisioned servers are used.

To digress, servers are used by web hosting companies as well. Web hosting companies use servers to store the files of websites. These files are delivered over the Internet to render websites accessible. The most reliable web hosting service providers are usually referred to as the “Best Website Hosting Company”, the “Best Windows Hosting Company”, the “Best Cloud Hosting Company” etc.

Serverless models are made available by cloud providers as two distinct services, which are, Function as a Service(FaaS) and Backend as a Service (BaaS). Serverless offers many benefits, which include enhanced scalability along with more flexibility, cost reduction, quicker time to release etc. Additionally, it does away with the need to purchase, provision and manage backend servers.

In this blog serverless’ security’s in-depth analysis will be provided, which will touch upon the meaning of serverless security and the risks involved in it.

Serverless’ Security’s Risks and Challenges

While a serverless model does away with the worries with regard to infrastructure-related operations, security concerns remain to be addressed in it. A serverless model requires protection because it doesn’t use detection system software or firewalls. Moreover, its architecture neither involves instrumentation agents nor protection methods, such as keys authentication or file transfer protocols. In serverless architecture, the data that is requested by any user is stored at the client-side. That is why the focus remains on data security, behavioral protection, permissions along with strong code for the purpose of protecting applications against library and coding risks.

Precautions need to be taken to secure serverless apps. That is because the serverless architecture makes use of a smaller approach than microservices. In it miniature, independent pieces of software are used, which interact through multiple APIs that become public on interacting with cloud providers. This mechanism leads to the creation of a security loophole that attackers can use to access the APIs and creates challenges with regard to the security of serverless apps.

The main security challenges for serverless have to do with configuration that is insecure, event-data injection, broken authentication and function permissions.  Additionally, inadequate monitoring of function and logging along with insecure third party dependencies and insecure storage of application secrets can be a security challenge for serverless. Let us touch upon each of these security risks individually.

Multiple features and setting are provided by cloud service providers. Hence, it is important to ensure that these settings provide reliable offerings that are authentic. When configurations are not taken care of, it can lead to risks related to security. Another risk involves event-data injection. Injection flaws are another type of serious vulnerability that exists. These take place when input, which is not trustworthy, is transmitted directly to an interpreter and then gets evaluated or executed. Numerous event sources are provided by serverless models. These are capable of triggering a serverless function’s execution. The potential attack surface is increased by such a huge set of event sources. This leads to the introduction of complexities with regard to the protection of serverless functions against event-data injections. Another challenge to serverless’ security are the risks related to function permissions. There are numerous independent functions in the serverless ecosystem. Each of these functions is responsible for a certain task. This interaction among functions might lead to functions becoming overprivileged with regard to permissions.

Broken authentication presents another security challenge for serverless. The microservice- like system design of serverless applications usually contains many distinct serverless functions that have their own purposes. Public web APIs might be exposed by some of these. It is important to implement powerful authentication schemes that ensure access control and protect all the relevant functions along with event type and trigger.

Inadequate monitoring of function and logging can be risky for serverless’ security. In the context of serverless’ security, it is essential to monitor and log events that are related to security in real-time. This aids in detecting malicious activities and in taking proper action to thwart those. It aids in averting cyber breaches in real-time. In serverless architecture, the monitoring and logging aspects exist in a cloud environment. Serverless architecture vendors usually provide very efficient logging facilities but these are not capable of ensuring a full security even audit trail in their basic configuration.

Third party dependencies that are not secure can be a risk to serverless’ security. A serverless function is supposed to be a tiny piece of code, which carries out a single discrete task. Often, for carrying out such a task, the serverless function needs to rely on open source libraries and third party software. These third party dependencies can render serverless applications vulnerable to cyber attacks. Insecure storage of application secrets is another potential threat to the security of serverless. In this day and age applications are growing in both, scale as well as complexity. Hence, it becomes extremely crucial to store and maintain properly application secrets, which include database credentials, API keys and encryption keys along with the settings for sensitive configuration. A common mistake, which causes security risks, has to do with the storage of application secrets within configuration files or database configurations in the form of plain text. This enables any user to gain access to these, if the user has “Read” permission. Environmental variables are used for data across the executions of serverless function.  There is always risk associated with such variables as data can be leaked by these to unauthorized entities. These are some of the main security risks for serverless that need to be addressed adequately to ensure the security of serverless.

Source: https://www.htshosting.org/knowledge-base/website-security/107/serverless-security-risks