Best practices for serverless security

The ability of serverless technology to speed up the software development process is one of the primary reasons its adoption has grown recently. It enables programmers to delegate server infrastructure maintenance to a Cloud Service Provider (CSP) and focus on application performance operations of the application. However, the primary issue with serverless is that the CSP is only in charge of the security of the cloud rather than security in the cloud. As a result, the serverless application faces the same threats and weaknesses as traditional apps and has to deal with specific security issues related to the serverless design. Application developers must therefore assume accountability for their serverless applications by following best practices.

Serverless security

A cloud computing operating model is serverless. Applications rely on managed services under the serverless architecture, eliminating the need to manage, patch, and secure infrastructure and virtual machines. Serverless applications use function-as-a-service, or FaaS, and managed cloud services.

Organizations' perspectives on application security need to change to accommodate serverless security. Organizations must add security to the apps hosted by third-party cloud providers by securing the functions within them and the program itself using Next Generation Firewalls. The installation of this layer of protection helps organizations maintain and improve their security posture by ensuring effective application hardening and least privilege access control, ensuring that each function performs as intended.

Serverless security risks

Serverless technology has its security risks that must be considered and addressed. Some of the leading security risks associated with serverless computing include the following:

Function Event-Data Injection

Some of the most dangerous vulnerabilities are injection issues. They occur if unreliable input is sent straight to an interpreter for execution or evaluation. Most serverless architectures offer a wide range of event sources that can start a serverless function. When trying to defend serverless functions from event-data injections, this large number of event sources adds complexity and widens the possible attack surface. It is made worse because serverless architectures are less well-known than web environments, where developers know which message components shouldn't be trusted (such as GET/POST parameters, HTTP headers, and other components).

Some of the most prevalent injection vulnerabilities in serverless architectures include the following:

• SQL injection
• NoSQL injection
• Object deserialization attacks
• Server-Side Request Forgery (SSRF)

Broken authentication

Broken authentication can create serverless security risks by allowing an attacker to exploit weaknesses in an authentication mechanism and gain unauthorized access to a serverless application or its data. It can lead to data breaches, unauthorized transactions, identity theft, or session hijacking. Here are some ways in which broken authentication can create serverless security risks:

• Access control - serverless applications rely on authentication mechanisms to control access to the application and its data. If authentication is broken, an attacker can bypass these mechanisms and gain access to sensitive data or functions. It can lead to data breaches, unauthorized transactions, or other security incidents.
• Identity theft - broken authentication can allow an attacker to impersonate a legitimate user or application and perform unauthorized actions on behalf of that user or application. It can result in financial loss, data breaches, and other security incidents.
• Session hijacking - serverless applications use sessions to maintain user state across multiple requests. If authentication is broken, an attacker can hijack a user's session and gain access to the user's data or perform unauthorized actions. It can lead to data breaches, unauthorized transactions, or other security incidents.
• Cross-site scripting (XSS) - broken authentication can allow an attacker to inject malicious code into a serverless application, leading to XSS attacks. It can allow an attacker to steal sensitive data or perform unauthorized actions on behalf of the user.

Insecure application code

Serverless applications are written using code, and insecure code can lead to a range of security risks by introducing vulnerabilities that attackers exploit to compromise the confidentiality, integrity, or availability of serverless applications or data. Insecure code can lead to injection attacks, such as SQL injection or code injection, cross-site scripting (XSS) vulnerabilities, insecure data storage, and broken access controls. These vulnerabilities allow attackers to execute arbitrary code, access sensitive data, steal user data, perform unauthorized actions, or gain unauthorized access to sensitive data or functions.

Third party dependencies

Third-party dependencies can pose a significant security risk in serverless environments because they introduce a potential attack surface beyond the developer's control. These dependencies can include libraries, frameworks, and modules, which may contain vulnerabilities or be subject to compromise. If attackers exploit a vulnerability in a third-party dependency, they can potentially gain access to sensitive data or resources in the serverless application. It's important for developers to carefully vet third-party dependencies, keep them up-to-date, and regularly monitor for vulnerabilities and security issues to minimize the risk of a security breach. Third-party dependencies can pose a security risk in several ways:

• Vulnerabilities - third-party dependencies may contain vulnerabilities or security flaws that can be exploited by attackers. It is of particular concern in serverless environments, where functions may be reused across different applications or environments, potentially amplifying vulnerabilities.
• Malicious code - third-party dependencies may contain malicious code or backdoors that can be used by attackers to gain unauthorized access or control of serverless resources.
• Lack of control - serverless functions may rely on third-party dependencies maintained by external developers or organizations, which can make it difficult for organizations to control or monitor the security of these components.
• Supply chain attacks - attackers may compromise third-party dependencies by injecting malicious code or backdoors into these components, which can then be propagated to serverless functions or applications that rely on them.

Overprivileged function permissions and roles

Overprivileged function permissions and roles can create serverless security risks by granting excessive access to serverless functions, which allows attackers to execute unauthorized actions and compromise the confidentiality, integrity, or availability of serverless applications or data. Here are some ways in which overprivileged function permissions and roles can cause serverless security risks:

• Data breaches - overprivileged function permissions and roles can allow attackers to access sensitive data, leading to data breaches and potential financial or reputational damage.
• Malicious actions - overprivileged function permissions and roles allow attackers to execute malicious actions, such as modifying or deleting data, stealing user credentials, or launching further attacks.
• Compliance violations - overprivileged function permissions and roles can result in compliance violations, such as violating data protection regulations, which can result in regulatory fines and legal action.
• Resource exhaustion - overprivileged function permissions and roles can result in resource exhaustion, such as excessive CPU usage or storage, leading to degraded performance or denial-of-service attacks.

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Best practices for serverless security

To address these security risks, it is important to implement a comprehensive security strategy. Here are some of the best practices for securing your serverless application.

Implementing proper identity and access management (IAM)

Identity and Access Management (IAM) refers to a set of policies, technologies, and practices that enable organizations to manage and control access to their digital resources. IAM systems help organizations ensure that only authorized individuals or systems can access their sensitive information and applications, while also helping to protect against unauthorized access, data breaches, and other security threats.

IAM systems typically involve the creation, management, and deletion of digital identities (e.g., usernames, passwords, biometric data, etc.) for employees, contractors, partners, and other users. These identities are then used to control access to various digital resources, such as applications, data, networks, and devices. IAM systems can also enforce policies related to user authentication, authorization, and audit trails.

Some popular IAM technologies and solutions include single sign-on (SSO), multi-factor authentication (MFA), role-based access control (RBAC), and privileged access management (PAM). IAM is an important aspect of modern cybersecurity, particularly as organizations continue to move towards cloud-based services and remote workforces.

IAM enables serverless security by providing fine-grained access controls to serverless functions and resources. It means that IAM can be used to grant or restrict access to specific functions based on a user's identity or other attributes. For example, IAM policies may be used to restrict access to certain functions or resources based on a user's role within an organization, specific network, or device characteristics. IAM can be employed to manage permissions and access to resources at the API level. It means that IAM policies can be used to control access to serverless functions and resources based on specific API calls or requests. It can help to prevent unauthorized access or misuse of serverless resources and functions.

IAM also enables organizations to audit and monitor access to serverless resources and functions. IAM policies can be leveraged to create detailed audit logs of user activity and access to serverless resources to identify and respond to security incidents or breaches.

Encrypting data in transit and at rest, and using secure key management practices

Encrypting data in transit and at rest, as well as using secure key management practices, are essential best practices for serverless security. Encrypting data in transit means that any data transmitted between different components or services in a serverless architecture should be encrypted using secure encryption protocols, such as Transport Layer Security (TLS) or Secure Sockets Layer (SSL). It ensures that any sensitive data being transmitted cannot be intercepted or read by unauthorized parties.

Encrypting data at rest means that any data stored in databases, caches, or other storage systems should be encrypted using strong encryption algorithms, such as Advanced Encryption Standard (AES). It ensures that even if someone gains unauthorized access to the storage systems, the data is still protected and can not be read.

In addition to encryption, secure key management practices should also be followed to ensure that encryption keys are kept secure and are not compromised. It includes using strong and unique encryption keys for each application or service, rotating encryption keys regularly, and storing encryption keys securely in a separate location from the data they are protecting.

Implementing these best practices for serverless security can help ensure that sensitive data remains secure and protected from unauthorized access or attacks.

Logging and monitoring for security events

Logging and monitoring are essential for serverless security. Since serverless architectures rely on third-party cloud providers for infrastructure, traditional security controls like firewalls and intrusion detection systems may not be applicable. Logging involves collecting and analyzing system activity data to gain visibility into potential security threats or vulnerabilities, track compliance, and analyze application events. Monitoring, on the other hand, involves real-time analysis of system activity data to detect and respond to security incidents as they occur. It includes metrics such as function invocation times, memory usage, and network traffic. Both logging and monitoring can identify potential threats and vulnerabilities, leading to rapid incident response and improved serverless security.

Time out your functions

The timeout function in serverless computing is a critical security feature that helps prevent malicious actors from exploiting vulnerabilities and causing damage to a system. When a function is executed, the serverless platform sets a maximum time limit for the function to run. If the function exceeds this time limit, the platform terminates the function's execution.

This feature helps protect the system from various types of attacks, including denial-of-service attacks where an attacker could run a function indefinitely to consume system resources and prevent legitimate requests from being processed.

By setting a timeout limit, the serverless platform can also help prevent other security issues, such as memory leaks and infinite loops. It ensures that the resources allocated to a function are released when no longer needed, reducing the risk of resource exhaustion attacks.

Overall, the timeout function is a crucial security measure in serverless computing, as it helps ensure that functions are executed in a secure and controlled environment.

Cut down on third-party dependencies

To mitigate the security risks associated with third-party dependencies, organizations should implement the following best practices:

• Regularly monitor and update third-party dependencies to ensure they are up-to-date and free of vulnerabilities or security flaws.
• Use trusted sources for third-party dependencies and verify that they have been audited for security issues.
• Implement security controls, such as access controls and monitoring, to help detect and prevent unauthorized access or misuse of serverless resources.
• Use tools such as software composition analysis (SCA) to detect vulnerabilities in third-party dependencies and prioritize remediation efforts.

By following these best practices, organizations can reduce the risk of security incidents related to third-party dependencies in serverless environments.

Secure software development lifecycle

Secure software development lifecycle (SDLC) practices can help improve serverless security by incorporating security considerations into every stage of the development process. By integrating security into the SDLC, developers can identify potential security risks and vulnerabilities early in the development process, which allows them to address these issues before they become even more difficult and expensive to fix. SDLC practices include threat modeling, secure coding practices, code reviews, testing, or vulnerability scanning. By implementing SDLC practices, organizations can build more secure serverless applications, reduce the risk of security breaches, and improve their overall security posture.

Here are the typical stages of the SDLC for serverless security:

• Requirements gathering - this stage involves identifying the specific security requirements of the serverless application, including compliance requirements, data privacy regulations, and any other relevant security policies. The security requirements should be documented and communicated to all stakeholders, including developers, testers, and operations teams.
• Design - during this stage, the security architecture of the serverless application is designed. It includes identifying the security controls and mechanisms that will be used to protect the application, such as encryption, access controls, and threat detection.
• Development - in this stage, the actual coding of the serverless application takes place. Developers should use secure coding practices to minimize the risk of vulnerabilities such as injection attacks, cross-site scripting (XSS), and other common security threats.
• Testing - in this stage, the serverless application is tested for security vulnerabilities. It includes automated testing for common vulnerabilities such as SQL injection and cross-site scripting, as well as manual testing for more complex security issues.
• Deployment - once the serverless application has been tested and the issues have been resolved, it is deployed to the production environment. This stage should include reviewing the deployment process to ensure that it is secure and that all security controls are functioning as expected.
• Operations and maintenance - after the serverless application is deployed, ongoing monitoring and maintenance are necessary to ensure it remains secure. It includes monitoring for security incidents, patching vulnerabilities, and implementing all necessary security updates.
• Decommissioning - finally, when the serverless application is no longer needed, it should be decommissioned in a secure manner. It includes deleting any data or other assets associated with the application and ensuring that all security controls are disabled.

By following these stages, developers can ensure that serverless applications are developed, tested, and deployed in a secure manner and that they remain secure throughout their lifecycle.

Use of custom function permissions

Custom function permissions are an important aspect of serverless security, as they allow you to control access to specific functions within your serverless application. It enables you to define which AWS Identity and Access Management (IAM) roles, Amazon Cognito user pools, or client IDs can invoke your function. It can help prevent unauthorized access and misuse of your serverless resources.

By granting only the necessary permissions to each function, you can limit the potential damage from any security breaches that may occur. For example, if a function has read-only access to a specific database table, it cannot be used to modify or delete data from that table, even if it is compromised by an attacker.

Additionally, custom function permissions allow you to easily implement the principle of least privilege - a fundamental security principle stating that each user or system component should only have the minimum access necessary to perform the job. It reduces the attack surface and limits the potential damage of any security breaches.

In summary, custom function permissions are a critical component of serverless security that allows you to control access to specific functions within your serverless application, limit the potential damage of security breaches, and implement the principle of least privilege.

Don’t rely solely on WAF protection

While Web Application Firewall (WAF) protection is a valuable security measure for serverless environments, it is vital not to rely solely on it. WAF is not foolproof and may not catch all potential threats. It may also generate false positives that can cause legitimate traffic to be blocked. Therefore, organizations should consider implementing other security measures in conjunction with WAF, such as secure coding practices, access control mechanisms, encryption of sensitive data, vulnerability management, and logging and monitoring tools.

Additionally, regular testing and refinement of security measures, along with employee training and awareness, can help maintain a strong serverless security posture. By implementing a comprehensive security strategy that includes multiple layers of defense, organizations can minimize the risk of security incidents and protect their critical data and resources in serverless environments.

Implementing threat detection tools, and establishing a process for responding to security incidents

Serverless security can be improved by implementing threat detection tools and establishing an incident response plan. The first step is to identify potential security threats that could affect the serverless environment, such as unauthorized access, data breaches, and malicious code injections. Next, organizations should select and deploy appropriate threat detection tools, such as intrusion detection systems, vulnerability scanners, and log analysis tools. These tools should be configured to monitor and detect potential threats in the serverless environment.

In addition, an incident response plan should be developed to address potential security incidents. This plan should include guidelines for identifying, reporting, and containing security incidents, as well as procedures for mitigating the impact of the incident. It is also important to regularly test and refine the incident response plan to ensure its effectiveness. By implementing these measures, organizations can proactively identify and respond to potential security threats, protecting their critical data and resources in serverless environments.

Ensure secure communication between serverless services and resources

Ensuring secure communication between serverless services and resources is essential to maintaining the overall security of serverless architectures. By implementing secure communication protocols, access control, and monitoring tools, organizations can minimize the risk of unauthorized access, data interception, or other security threats. Secure communication methods such as VPNs andencryptedprotocols can protect data intransit between serverless services.Accesscontrolensures that only authorized users or services can access specific resources. Monitoring tools can visualize communication patterns and identify potential security threats in realtime, allowing organizations to respond quickly and reduce the risk of security breaches. Here are some best practices to consider:

• Use secure protocols - all communication between serverless services and resources should use secure protocols such as HTTPS, SSL, or TLS. These protocols encrypt the communication and provide authentication, ensuring that the data is not tampered with and the parties involved are who they claim to be.
• Implement access controls - use access controls to ensure that only authorized services and resources can communicate with each other. It can be done through the use of authentication, authorization, and least privilege access control principles.
• Use Virtual Private Networks (VPNs) - VPNs create a secure connection between different networks, allowing serverless services and resources to communicate with each other securely, even across public networks like the Internet.
• Secure service-to-service communication - use secure communication protocols like mutual TLS (mTLS) or JSON Web Tokens (JWTs) to authenticate and authorize service-to-service communication.
• Monitor communication - monitor communication between serverless services and resources to detect anomalies or suspicious activity. It can be done through the use of logs, intrusion detection systems, and other monitoring tools.

By following these best practices, you can ensure that communication between serverless services and resources is secure and protected from unauthorized access or attacks.

Secret Management

Secret management helps serverless security by providing a secure way to store and manage secrets, such as passwords and API keys, which serverless functions require to access various resources. A serverless architecture can be vulnerable to unauthorized access if these secrets are not adequately protected. Secret management tools offer encryption, access control, and auditing features to ensure that secrets are only accessible to authorized users and not exposed to potential attackers. By using secret management tools, serverless applications can more easily ensure that sensitive information is protected and the application's overall security is maintained. This can help intercept data breaches and other security incidents that could compromise the integrity and confidentiality of the application and its users. Several popular tools are available for secret management and can be used in a serverless architecture. Here are a few examples:

• AWS Secrets Manager - AWS Secrets Manager is a fully managed service from Amazon Web Services that allows you to effortlessly rotate, manage, and retrieve secrets throughout their lifecycle. It offers encryption, access control, and integration with other AWS services.
• HashiCorp Vault - HashiCorp is an open-source tool that provides secure secret storage and access control. It can be used to store and manage a variety of secrets, including passwords, certificates, and API keys. It offers features such as dynamic secrets, audit logging, and encryption.
• Azure Key Vault - Azure Key Vault is a cloud-based service from Microsoft Azure that offers secure storage and management of cryptographic keys, certificates, and secrets. It offers access control, auditing, and integration with other Azure services.
• Google Cloud KMS - This fully managed key management service from Google Cloud allows you to easily manage and rotate cryptographic keys and secrets. It offers encryption, access control, and integration with other Google Cloud services.
• 1Password - 1Password is a password manager which allows you to securely store and manage passwords, API keys, and other secrets. It offers features such as encryption, access control, auditing, and integrations with popular development tools and platforms.
• Doppler - Doppler is a secret management tool that can help in serverless security by providing a secure way to store and manage secrets for serverless applications. Doppler enables teams to centralize secrets management, prevent secrets sprawl, and ensure secrets are kept safe throughout their lifecycle. With Doppler, you can store and manage a variety of secrets, including API keys, database credentials, and encryption keys. Doppler provides a simple API for accessing secrets that serverless functions and other applications can use.

Importance of implementing best practices for serverless security

Implementing best practices in serverless security is important for several reasons:

• Protecting sensitive data - serverless architectures typically involve the use of cloud services and third-party APIs, which can potentially expose sensitive data to unauthorized access. Implementing best practices in serverless security can help protect sensitive data from being compromised.
• Maintaining compliance - many industries are subject to regulatory compliance requirements, which often include security standards. Organizations can maintain compliance with these standards by implementing best practices in serverless security.
• Preventing security breaches - security breaches can result in financial losses, damage to reputation, and legal liabilities. Implementing best practices in serverless security can help prevent security breaches from occurring.
• Ensuring availability - serverless architectures are designed to scale dynamically based on demand, which can put a strain on resources. Implementing best practices in serverless security can help ensure that the resources are available to handle the load.
• Reducing operational costs - security breaches can result in additional operational costs, such as incident response and recovery. By implementing best practices in serverless security, organizations can reduce the risk of security breaches and associated costs.

Overall, implementing best practices in serverless security is essential for ensuring the confidentiality, integrity, and availability of resources in serverless architectures.

Conclusion

Security risks exist in all types of platforms, and serverless is no different. In conclusion, securing serverless technology requires a multi-layered approach and countermeasures. In this article, we looked at the risks of serverless computing and best practices for serverless security.