CVE-2015-4165 in Elasticsearch
Summary
by MITRE
The snapshot API in Elasticsearch before 1.6.0 when another application exists on the system that can read Lucene files and execute code from them, is accessible by the attacker, and the Java VM on which Elasticsearch is running can write to a location that the other application can read and execute from, allows remote authenticated users to write to and create arbitrary snapshot metadata files, and potentially execute arbitrary code.
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Analysis
by VulDB Data Team • 11/24/2024
The vulnerability identified as CVE-2015-4165 represents a critical security flaw in Elasticsearch versions prior to 1.6.0 that stems from improper access controls within the snapshot API functionality. This weakness creates a dangerous attack vector where authenticated users can manipulate snapshot metadata files, potentially leading to arbitrary code execution on the target system. The vulnerability specifically exploits the interaction between Elasticsearch's snapshot capabilities and the underlying Lucene file system architecture, where the Java Virtual Machine running Elasticsearch can write to directories accessible by other applications that can read and execute code from those locations. The security implications extend beyond simple data manipulation as they encompass full system compromise potential.
The technical exploitation of this vulnerability relies on the presence of multiple concurrent applications on the same system where one application can read and execute code from Lucene files, while the Elasticsearch instance can write to locations accessible by that application. This creates a privilege escalation scenario where authenticated users can leverage the snapshot API to write malicious metadata files that will be executed by the other application. The flaw is categorized under CWE-269, which deals with improper privilege management, and specifically relates to CWE-732, improper limitation of a pathname to a restricted directory. The vulnerability demonstrates a classic case of inadequate input validation and insufficient access control mechanisms in the snapshot management functionality.
From an operational perspective, this vulnerability allows remote authenticated attackers to perform arbitrary file creation and modification operations within the Elasticsearch environment, potentially leading to complete system compromise. The attack requires an authenticated user account with sufficient privileges to access the snapshot API, but once exploited, the attacker can create malicious snapshot metadata files that will be executed by the system's Java Virtual Machine. This creates a persistent threat vector that can be used for privilege escalation, data exfiltration, or further network infiltration. The vulnerability aligns with ATT&CK technique T1059.007 for command and scripting interpreter and T1078.004 for valid accounts, as it leverages legitimate authenticated access to execute malicious operations.
The mitigation strategy for CVE-2015-4165 involves immediate patching of Elasticsearch installations to version 1.6.0 or later, which includes proper access controls and validation mechanisms for snapshot operations. Organizations should also implement network segmentation to isolate Elasticsearch instances from other applications that might be able to read and execute code from the same file system locations. Additional security measures include restricting file system permissions for Elasticsearch data directories, implementing strict access controls for snapshot API endpoints, and monitoring for unauthorized snapshot creation activities. System administrators should also consider implementing principle of least privilege for all Elasticsearch user accounts and regularly audit snapshot operations to detect potential malicious activity. The vulnerability highlights the importance of proper file system isolation and access control in distributed systems where multiple applications share common resources and execution environments.