CVE-2018-1284 in Hive
Summary
by MITRE
In Apache Hive 0.6.0 to 2.3.2, malicious user might use any xpath UDFs (xpath/xpath_string/xpath_boolean/xpath_number/xpath_double/xpath_float/xpath_long/xpath_int/xpath_short) to expose the content of a file on the machine running HiveServer2 owned by HiveServer2 user (usually hive) if hive.server2.enable.doAs=false.
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Analysis
by VulDB Data Team • 05/26/2020
The vulnerability described in CVE-2018-1284 represents a critical information disclosure flaw within Apache Hive's XPath User Defined Functions that can be exploited by malicious actors to access sensitive files on the HiveServer2 host system. This vulnerability specifically affects Apache Hive versions ranging from 0.6.0 through 2.3.2, creating a persistent security risk across multiple generations of the platform. The flaw manifests when the hive.server2.enable.doAs configuration parameter is set to false, which removes important security boundaries that would otherwise prevent unauthorized file access. The vulnerability is categorized under CWE-200, which deals with improper exposure of sensitive information, and aligns with ATT&CK technique T1005 for data from local system and T1041 for data exfiltration.
The technical mechanism behind this vulnerability involves the exploitation of XPath UDFs within Hive's query processing framework. These functions are designed to parse XML data using XPath expressions, but when improperly configured with hive.server2.enable.doAs=false, they can be manipulated to read arbitrary files from the file system. The malicious user can craft XPath expressions that reference local file paths, allowing them to extract content from files owned by the HiveServer2 process user, typically the hive user account. This occurs because the XPath functions do not properly validate or sanitize the file paths used in their operations, creating a path traversal condition that enables unauthorized file access. The vulnerability specifically impacts the xpath, xpath_string, xpath_boolean, xpath_number, xpath_double, xpath_float, xpath_long, xpath_int, and xpath_short UDFs, making it a comprehensive issue affecting the entire XPath function family within the affected Hive versions.
The operational impact of this vulnerability extends far beyond simple information disclosure, as it can lead to complete compromise of the Hive server environment and potentially broader system access. Attackers can leverage this vulnerability to extract configuration files, database credentials, user data, and other sensitive information that may be stored in files accessible to the hive user account. The risk is particularly severe because HiveServer2 typically runs with elevated privileges and may have access to sensitive data stores, making the extracted information potentially valuable for further attacks. The vulnerability also demonstrates poor input validation practices and highlights the importance of secure coding principles in database query processing systems. Organizations using affected Hive versions face significant risk of data breaches and compliance violations, as this vulnerability can be exploited without requiring authentication to the Hive system itself, making it particularly dangerous in environments where Hive is exposed to untrusted users.
Mitigation strategies for CVE-2018-1284 should focus on immediate configuration changes and system hardening measures. The primary and most effective mitigation is to set hive.server2.enable.doAs=true, which enables the proper user context switching that prevents unauthorized file access. Organizations should also implement strict access controls and authentication mechanisms to limit who can execute XPath functions within Hive. Additionally, regular updates to Apache Hive to versions that have patched this vulnerability should be prioritized, with the specific patch addressing this issue available in Hive versions beyond 2.3.2. Network segmentation and monitoring should be implemented to detect unusual XPath query patterns that might indicate exploitation attempts. Security teams should also consider implementing file system access controls that limit the hive user's access to only necessary files and directories, reducing the potential impact of successful exploitation. The vulnerability serves as a reminder of the critical importance of secure configuration management and the need for regular security assessments of database systems that handle sensitive data.