CVE-2018-13390 in Cloudtoken
Summary
by MITRE
Unauthenticated access to cloudtoken daemon on Linux via network from version 0.1.1 before version 0.1.24 allows attackers on the same subnet to gain temporary AWS credentials for the users' roles.
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Analysis
by VulDB Data Team • 03/14/2020
The vulnerability described in CVE-2018-13390 represents a critical security flaw in the cloudtoken daemon implementation on Linux systems. This daemon is designed to facilitate secure credential management for AWS services, but the flaw allows unauthorized network access that bypasses proper authentication mechanisms. The vulnerability specifically affects versions 0.1.1 and earlier of the cloudtoken daemon, creating a persistent security risk for organizations relying on this credential management solution. The flaw exists within the network service implementation that handles authentication requests, allowing attackers to exploit a network-based attack vector without requiring valid credentials or prior access to the system.
The technical nature of this vulnerability stems from improper access control implementation within the cloudtoken daemon's network interface. Attackers on the same network subnet can exploit this weakness to establish unauthorized communication with the daemon and request temporary AWS credentials. This represents a classic case of insufficient authorization checks where the daemon fails to properly validate incoming network requests before processing credential requests. The vulnerability aligns with CWE-284 which addresses improper access control issues, specifically targeting the lack of proper authentication mechanisms in network services. The daemon's network stack appears to accept requests without verifying the identity or authorization status of connecting entities, creating an open door for malicious actors to obtain temporary AWS credentials.
The operational impact of this vulnerability extends beyond simple credential theft, as attackers can potentially escalate their access to full AWS service capabilities through the temporary credentials obtained. This temporary credential access allows attackers to perform actions within the scope of the users' AWS roles, potentially leading to data exfiltration, service disruption, or further lateral movement within the AWS environment. The attack vector is particularly concerning because it requires minimal prerequisites - simply being on the same network subnet provides sufficient access to exploit the vulnerability. This aligns with ATT&CK technique T1566 which covers credential harvesting through network-based attacks, and T1078 which addresses legitimate credentials usage for persistence and privilege escalation.
Organizations should immediately implement mitigation strategies including updating to version 0.1.24 or later of the cloudtoken daemon where the vulnerability has been patched. Network segmentation and firewall rules should be implemented to restrict access to the daemon's network ports, particularly preventing external access from untrusted subnets. Additional monitoring should be deployed to detect unusual credential requests or network activity patterns that might indicate exploitation attempts. The vulnerability demonstrates the importance of proper network access controls and authentication mechanisms, as outlined in security frameworks such as NIST SP 800-53 controls CM-7 and AC-3 which address configuration management and access control requirements. Regular security assessments and vulnerability scanning should be conducted to identify similar unauthenticated access points within the organization's infrastructure.