CVE-2022-2385 in aws-iam-authenticator
Summary
by MITRE • 07/12/2022
A security issue was discovered in aws-iam-authenticator where an allow-listed IAM identity may be able to modify their username and escalate privileges.
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Analysis
by VulDB Data Team • 07/23/2022
The aws-iam-authenticator vulnerability identified as CVE-2022-2385 represents a critical privilege escalation flaw within the Kubernetes authentication mechanism that leverages AWS Identity and Access Management credentials. This security issue affects the aws-iam-authenticator component which serves as a bridge between AWS IAM identities and Kubernetes RBAC systems, enabling secure authentication for Kubernetes clusters through AWS credentials. The vulnerability stems from improper validation of user identities during the authentication process, specifically allowing authenticated IAM users to manipulate their identity claims within the authentication token.
The technical flaw manifests in the way the authenticator processes and validates IAM identity information when generating Kubernetes authentication tokens. An attacker with access to a legitimate IAM identity that has been allow-listed for authentication can exploit a weakness in the token generation process to modify their username or identity attributes. This modification allows them to potentially gain elevated privileges within the Kubernetes cluster by impersonating higher-privileged identities or bypassing existing access controls. The vulnerability operates at the intersection of identity management and access control, creating a path for privilege escalation that violates the principle of least privilege. This flaw directly relates to CWE-285 which addresses improper authorization in authentication systems, and specifically targets the authentication token manipulation aspects of identity validation.
The operational impact of this vulnerability extends beyond simple privilege escalation to potentially compromise entire Kubernetes clusters and their underlying infrastructure. An attacker exploiting this vulnerability could gain access to sensitive cluster resources, manipulate workloads, access confidential data, and potentially move laterally within the cluster environment. The implications are particularly severe in multi-tenant environments where proper isolation between users and workloads depends on robust authentication and authorization controls. Organizations relying on aws-iam-authenticator for cluster access control face significant risk as this vulnerability could enable attackers to bypass existing security controls and gain unauthorized access to critical cluster operations. The attack vector requires only access to an existing IAM identity, making it particularly dangerous as it can be exploited by both internal and external threat actors who have obtained legitimate credentials.
Mitigation strategies for CVE-2022-2385 should focus on immediate patching of the aws-iam-authenticator component to address the token validation weakness. Organizations should implement additional monitoring and logging of authentication events to detect suspicious identity modifications or privilege escalation attempts. The principle of least privilege should be reinforced by carefully reviewing and limiting the IAM identities that are allow-listed for cluster access. Network segmentation and additional authentication layers such as multi-factor authentication should be considered to reduce the attack surface. Security teams should also implement continuous monitoring of authentication token generation and validation processes, ensuring that identity claims cannot be modified without proper authorization. The vulnerability highlights the importance of validating identity information at multiple points in the authentication flow and implementing proper input sanitization and validation mechanisms. Organizations should also consider implementing automated security scanning of their authentication components and establishing incident response procedures specifically tailored to authentication-related vulnerabilities. This vulnerability demonstrates the critical need for robust identity validation in cloud-native environments and aligns with ATT&CK technique T1548.003 which covers abuse of cloud services for privilege escalation.