Mitigating Cloud Attack Paths from Non-Human Identity Sprawl

Cloud Security: The Growing Threat of Non-Human Identity Sprawl

Cloud environments have introduced unprecedented flexibility and scalability, but they also bring new security challenges. Among the most critical, yet often overlooked, is the phenomenon of non-human identity sprawl and the subsequent emergence of “ghost credentials.” These represent a significant blind spot, creating novel attack paths that threat actors can exploit to gain unauthorized access and compromise cloud systems. According to Dark Reading, dormant non-human identities lead to hidden identity risks, a concern highlighted by security researcher Aleksandr Krasnov, who has developed an open-source tool to identify these trust paths.

Understanding Non-Human Identities and Ghost Credentials

Non-human identities are the digital personas assigned to applications, services, managed identities, and automated processes within cloud infrastructures. Unlike human users, these identities often possess broad permissions to perform specific tasks, interact with other services, or access sensitive data programmatically. Examples include service accounts, API keys, container identities, and serverless function roles.

“Sprawl” occurs when these non-human identities proliferate without proper management. This can happen due to:

• Over-provisioning: Granting more permissions than necessary for a task (violating the principle of least privilege).
• Lack of Decommissioning: Failing to remove identities associated with retired applications or services.
• Poor Visibility: Inability to track which identities exist, what permissions they hold, and whether they are still actively used.

“Ghost credentials” refer to the access keys, tokens, or other authentication materials tied to these dormant or over-privileged non-human identities. Because they are often forgotten or overlooked, they become prime targets for attackers. A successful compromise of such a credential can grant an attacker a foothold with potentially extensive permissions, allowing for Lateral Movement, data exfiltration, or resource manipulation within the cloud environment.

The Attack Path: Exploiting Cloud Service Accounts and APIs

Attackers targeting cloud environments are increasingly sophisticated in their TTPs. The compromise of a non-human identity typically involves several stages:

1. Reconnaissance: Identifying publicly exposed API endpoints, misconfigured cloud resources, or leaked credentials.
2. Initial Access: Exploiting a weak or stolen non-human credential. This could be an API key hardcoded in an application, a service account with default permissions, or credentials exposed in a Supply Chain Attack.
3. Privilege Escalation & Lateral Movement: Once an attacker gains access via a non-human identity, they analyze its permissions. If the identity is over-privileged or has trust relationships with other services, the attacker can use these to escalate privileges or move laterally across the cloud environment. For instance, an identity with sts:AssumeRole permissions could be used to switch to a more powerful role.
4. Persistent Access: Establishing backdoors or creating new, hidden non-human identities to maintain access even if the initial point of compromise is remediated.

This method of exploitation is particularly insidious because non-human identity activities are often less scrutinized than human user activities, making securing cloud service accounts against ghost credentials a critical challenge for security teams.

Actionable Recommendations: Detecting Non-Human Identity Sprawl

Addressing the risk posed by non-human identity sprawl requires a proactive and comprehensive strategy. Organizations must prioritize robust identity and access management practices tailored for cloud-native ecosystems.

1. Inventory and Audit All Non-Human Identities: Create a definitive inventory of all non-human identities, including service accounts, managed identities, API keys, and application roles. Regularly audit their permissions and usage patterns. Leverage tools such as the open-source solution mentioned by Aleksandr Krasnov to map existing trust relationships and identify potential attack paths.

2. Implement and Enforce Least Privilege: Grant non-human identities only the absolute minimum permissions required to perform their intended function. Regularly review and revoke any unnecessary permissions. This is foundational to Zero Trust architectures and significantly limits potential damage from a compromise.

3. Regular Credential Rotation: Automate the rotation of API keys and other non-human credentials. Short-lived credentials, when feasible, dramatically reduce the window of opportunity for attackers to exploit stolen or leaked credentials.

4. Monitor Non-Human Identity Activity: Implement robust logging and monitoring for all non-human identity actions. Utilize SIEM or cloud-native logging services to detect anomalous behavior, such as unusual API calls, access from unexpected locations, or attempts to access unauthorized resources. This is key for mitigating cloud identity risks from unused credentials and detecting misuse.

5. Decommission Unused Identities: Establish a clear lifecycle management process for non-human identities. Promptly decommission and remove identities associated with retired applications, services, or projects.

6. Secure Development Practices: Integrate security into the development pipeline. Ensure developers are trained on secure coding practices, especially regarding API key management and secret storage. Avoid hardcoding credentials and utilize secure secret management solutions.

By systematically addressing non-human identity sprawl and aggressively managing ghost credentials, organizations can significantly harden their cloud security posture against this emerging and complex attack vector.