CVE-2018-3829 in Cloud Enterprise
Summary
by MITRE
In Elastic Cloud Enterprise (ECE) versions prior to 1.1.4 it was discovered that a user could scale out allocators on new hosts with an invalid roles token. An attacker with access to the previous runner ID and IP address of the coordinator-host could add a allocator to an existing ECE install to gain access to other clusters data.
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Analysis
by VulDB Data Team • 03/25/2020
Elastic Cloud Enterprise version 1.1.3 and earlier contained a critical authorization flaw that allowed attackers to escalate privileges and access sensitive cluster data through improper token validation mechanisms. This vulnerability specifically affected the allocator scaling functionality within the Elastic Cloud Enterprise platform, where the system failed to properly validate roles tokens during the allocation process. The flaw enabled unauthorized actors to provision new allocator instances on host systems using invalid or compromised roles tokens, effectively bypassing the intended access controls that should have restricted such operations to legitimate administrators or authorized entities.
The technical implementation of this vulnerability stemmed from inadequate authentication checks during the allocator provisioning workflow. When a user attempted to scale out allocators onto new hosts, the system relied on a roles token for authorization validation but failed to properly verify the token's authenticity and scope. Attackers could exploit this weakness by leveraging previously obtained runner IDs and coordinator-host IP addresses to inject malicious allocator instances into existing ECE deployments. This particular attack vector represents a privilege escalation vulnerability that aligns with CWE-287, which addresses improper authentication issues in software systems.
The operational impact of this vulnerability was severe as it allowed attackers to gain unauthorized access to data belonging to other clusters within the same ECE installation. Once an attacker successfully added an allocator with invalid roles token, they could potentially access and manipulate data from multiple cluster instances, creating a significant data breach risk. The vulnerability essentially enabled lateral movement within the Elastic Cloud Enterprise environment, allowing attackers to expand their access beyond the initial compromised entry point. This type of attack falls under the ATT&CK technique T1078.004 for Valid Accounts and T1041 for Exfiltration, as the compromised system could be used to extract sensitive data from other clusters.
Organizations running affected versions of Elastic Cloud Enterprise faced substantial risk of data exposure and unauthorized system access. The vulnerability required minimal prerequisites for exploitation, as attackers only needed access to existing runner IDs and IP addresses, which are often discoverable through network reconnaissance activities. This made the attack surface particularly concerning for enterprises relying on ECE for their elastic search deployments. The security implications extended beyond simple data access, as attackers could potentially modify cluster configurations, disrupt services, or establish persistent access points within the environment. The vulnerability highlighted the importance of proper token validation and access control mechanisms in distributed cloud environments where multiple tenants or clusters share the same infrastructure.
The recommended mitigation for this vulnerability involved upgrading to Elastic Cloud Enterprise version 1.1.4 or later, which included proper roles token validation and enhanced authorization controls for allocator provisioning operations. Organizations should also implement network segmentation and monitoring to detect unauthorized allocator additions to their ECE deployments. Additional security measures included regular audit of allocator instances, implementation of stricter access controls for coordinator hosts, and enhanced network monitoring to detect suspicious runner ID and IP address usage patterns. This vulnerability serves as a reminder of the critical importance of proper authentication and authorization mechanisms in cloud-based enterprise systems where multiple cluster instances may share common infrastructure resources.